A dealer will pay you 85–92% of your car's private-party value for the privilege of skipping Facebook Marketplace. That sounds like an easy call until you count the second number almost everyone forgets: in most states, trading in cuts the sales tax on your replacement car. Get both numbers on the table and the answer stops being a slogan — sometimes private wins by $2,000, sometimes the dealer's "lowball" actually pays more.
Buyers don't invent their discounts; they price a margin. A franchise dealer reconditions your car, floors it (borrows against it), and either retails it or wholesales it at auction. Each step costs money, and their offer reflects that. Rough national bands:
| Buyer | Typical offer (% of private-party) | Trade-off |
|---|---|---|
| Private sale | 100% | Your hours, your liability, your lowball messages |
| Online instant buyer | 85–90% | Firm number in minutes, no haggling, may deduct at pickup |
| Franchise dealer trade | 88–92% | One transaction, tax credit applies, easy loan payoff |
| Independent used-car lot | 90–95% | Better number, less polish, same paperwork help |
Two patterns matter. The discount is widest on rough or high-mileage cars — a dealer sees recon work, a private buyer sees "runs great." And clean, late-model, in-demand cars compress the gap toward 90%+, which is exactly where the tax credit starts flipping verdicts.
In roughly 40 states, sales tax on a replacement car is charged only on the difference between the new price and your trade-in allowance. Buy a $35,000 car with a $17,400 trade at 7% and you pay tax on $17,600 ($1,232) instead of $35,000 ($2,450). That $1,218 belongs in the dealer's column of your comparison.
Six places give no credit and tax the full purchase price regardless: California, Hawaii, Kentucky, Michigan, Virginia, and Washington DC. Five more (Alaska, Delaware, Montana, New Hampshire, Oregon) have no general sales tax, so the credit question is moot. Watch out for outdated articles — Texas and Maryland both allow the deduction now, but old no-credit lists still float around. Confirm with your state revenue agency before you sign anything; this is an estimate, not tax advice.
Say your car books at $20,000 private-party and you're buying a $35,000 replacement in a 7% credit state:
The breakeven lands at $18,271, or 91.4% of private value — a useful negotiating target. Any offer above it makes trading in the strictly better deal; anything below, the discount is costing you real money. Move the same numbers to California and the 87% offer loses by the full $2,150.
Private value, dealer offer, selling costs, tax rate, credit state — the verdict, margin, and breakeven offer in one click.
Open the Trade-In vs Private Sale Calculator →Private-sale costs are real but modest: $100–$250 detailing, $100–$400 for the small repairs that make photos look sellable, $15–$75 in listing fees, and whatever your state charges for title transfer and smog or safety certificates. Call it $300–$700 all-in for most cars.
The bigger cost is friction. Expect a week or three of messages, a few no-shows, test drives with strangers, and cash-or-payment-verification worries. On a $20,000 car, private's $932 edge over an 87% offer works out to roughly $150–$230 an hour for 4–6 hours of actual effort. Reasonable wage. On a $6,000 commuter where the edge is $280? Not so much.
For the wider picture of what cars cost to hold, the car depreciation calculator shows how fast the asset itself is shrinking, the auto loan calculator prices the replacement, and the car maintenance cost calculator tracks the running bills that make "sell vs keep" its own question.
Dealer and instant-buyer offers usually land at 85-92% of private-party value; independent used-car lots pay around 90-95%. On a $20,000 car, that's roughly $1,600-$3,000 you hand over for convenience, before counting the trade-in tax credit most states give you.
In the roughly 40 states that tax only the difference, the credit equals your sales-tax rate times the trade-in value. At 7%, a $17,400 trade saves $1,218 in tax. That is real money, but it rarely erases a 13% offer discount on its own — it closes the gap, so a 92% offer wins while an 85% one still loses. California, Hawaii, Kentucky, Michigan, Virginia, and DC give no credit at all.
Budget $300-$700: detailing ($100-$250), small repairs that make photos look right ($100-$400), listing fees ($15-$75), plus title transfer and any smog or safety certificate. Then weigh 4-6 hours of messages, test drives, and DMV paperwork against a dealer transaction that takes an afternoon.
Usually slightly less: instant buyers (Carvana, CarMax and similar) commonly pay 85-90% of private-party value versus 88-92% at franchise dealers. Their advantage is certainty — a firm number in minutes, no re-negotiation at the store, and they take cars with issues dealers would deduct for anyway.
When the offer is near breakeven (about 91-92% of private value in a 7% credit state), when your car needs work you don't want to fund, when you still owe on a loan (the dealer handles the payoff and any negative equity), or when the private market for your model is slow. Convenience is worth something; just price it consciously.