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Inside Presm: How an Investor Modelled a $935,000 Brisbane Purchase in 14 Minutes

A walkthrough of one investor's actual workflow on Presm — borrowing power, stamp duty, LMI, land tax, and loan repayment. The 14 minutes that replaced a $400 broker meeting.

A buyer in Sydney is looking at a $935,000 Brisbane house. Before they make an offer, they want to know what it costs to acquire, what it costs to hold, what their borrowing capacity actually supports, what land tax it adds to their portfolio, and what the after-tax cash flow looks like. Without Presm, that workflow takes 90 minutes across spreadsheets, two browser tabs of state revenue office calculators, a follow-up call with their broker, and a guess on land tax that turns out to be wrong.

With Presm, it takes 14 minutes and produces numbers the buyer can actually use to negotiate.

This post walks through that exact workflow as a real investor would run it, calculator by calculator, with the inputs and outputs at each step.

Step 1: Borrowing Power (3 minutes)

Before anything else, confirm the buyer can actually finance the purchase.

Inputs entered into the Borrowing Power Calculator:

Output:

The $935,000 purchase exceeds the capacity at 80% LVR (which would require an $748,000 loan against $830,000 capacity = fine) but exceeds capacity at 90% LVR. The buyer is going to need close to 80% LVR, meaning $187,000 of deposit plus stamp duty.

This is the first decision point. The buyer either drops the price band, increases the deposit (perhaps using equity from elsewhere), or accepts a tighter financial position.

Step 2: Stamp Duty (90 seconds)

Once the price is locked at $935,000, run the Stamp Duty Calculator.

Inputs:

Output:

The buyer now knows the duty bill exactly. No guesswork from a stale online calculator that hasn't updated for the 2025 QLD rates. The number flows into the cash-needed calculation.

Step 3: LMI (60 seconds)

Quick check on whether the 80% LVR path is locked in or whether 88-90% LVR with LMI is viable. Run the LMI Calculator.

Inputs:

Output:

At 88% LVR the buyer would need only $112,200 deposit plus stamp duty $31,240 = $143,400 cash. At 80% LVR the buyer needs $187,000 deposit + $31,240 duty = $218,240 cash.

The $74,840 cash difference is the practical question. The buyer has $200,000. Both paths are viable. The 80% LVR path saves the LMI premium ($20,300) but uses more cash. The 88% LVR path keeps cash for buffer and future investment.

Step 4: Land Tax Impact (3 minutes)

The buyer already owns one investment property in NSW with $580,000 land value. Adding a second property in Queensland creates a new state-by-state land tax exposure. Run the Land Tax Calculator.

Inputs (for Queensland portfolio after purchase):

Output:

For the existing NSW property:

Combined land tax across the portfolio: $0. Both properties sit under their respective state thresholds. This is a key reason to diversify across states — concentrating $1.06M of land value in either state would have triggered substantial land tax in NSW or moderate land tax in QLD.

Step 5: Loan Repayment Modelling (3 minutes)

Now the cash flow. Run the Loan Repayment Calculator.

Inputs:

Output:

For the investor, the year-one IO position is $890/week of mortgage cost. Against $620/week rent (estimated), the property is $270/week negatively geared before any expenses. After expenses (council, insurance, management, repairs at typical 25% of rent), net cash before tax is approximately -$540/week or -$28,000/year.

Adding depreciation of $9,500 (estimated for a 2018 build), net rental loss for tax is approximately -$37,500. Tax refund at 32% blended marginal rate: $12,000.

Net after-tax holding cost: $16,000/year, or $307/week.

Step 6: Rentvesting Model (4 minutes)

The buyer is currently renting in Surry Hills at $750/week. Run the Rentvesting Calculator to confirm the rentvesting case still works with this purchase.

Inputs:

Output:

The rentvesting position holds together. If the investor had instead waited to buy a Sydney unit, equivalent 10-year wealth created would be approximately $185,000 (lower due to slower Sydney unit growth).

What The 14 Minutes Replaced

Without Presm, the same workflow would have required:

Total: ~150 minutes, with several outputs being unreliable.

The Presm workflow integrated all of these in a single session with consistent assumptions across calculators. The buyer is now ready to make an informed offer.

What The Buyer Did Next

The buyer made an offer at $920,000 (negotiation room from $935,000 asking) with subject-to-finance clause and 30-day settlement. The vendor accepted at $925,000. The buyer's cash deployed was $185,000 + $31,240 stamp duty + $3,500 other costs = $219,740, well within the $200,000 cash budget plus $20,000 of family bridging.

After 12 weeks, settlement completed. The property was leased at $625/week within 14 days, slightly above the buyer's $620 estimate.

Where The Tools Compound

The single biggest value of running multiple Presm calculators in sequence is consistency. The borrowing capacity number flows into the loan size in Loan Repayment. The rental yield estimate flows into the cash position. The land tax number flows into the holding cost. Each calculator's outputs feed into the next, and the buyer ends up with a single coherent picture rather than five disconnected estimates.

For broader strategy context that runs alongside the calculator workflow, see our property investment strategy 2026 guide. For first-time investor process, see our first investment property beginners guide.

Frequently Asked Questions

Are Presm calculations more accurate than other online tools?

Presm calculations use current FY 2025-26 rates and thresholds across all major Australian jurisdictions. Many online tools use outdated rates from prior years, particularly for state-specific stamp duty and land tax. The accuracy difference can be $5,000-$30,000 on a single transaction.

Can I save my calculations and revisit them?

Yes, with an account. Each calculation can be saved to your account and revisited as your scenarios evolve. This is included with your account at no additional cost.

Do Presm tools account for the Stage 3 tax cuts?

Yes. All marginal tax rate calculations across the Presm calculators use the FY 2025-26 brackets — 16%, 30%, 37%, 45% at thresholds of $18,200, $45,000, $135,000, and $190,000.

How does Presm handle interstate scenarios?

Each calculator allows state selection where state-specific rules apply. Stamp duty, land tax, and entity land tax calculators all run state-specific calculations and can compare across states for the same scenario.

Can I use Presm for SMSF property scenarios?

The Borrowing Power and Loan Repayment calculators support modelling for SMSF property purchases, including LRBA-specific assumptions. Note that SMSF lending typically runs at higher rates than personal lending, which is reflected in the calculator's defaults.