Hardly most.
I have seen and done false where the offer comes after the inspection, but in my experience, you agree upon a price first, then inspect to verify that the airplane is as-represented and there are no hidden gotchas or airworthiness discrepancies.
If there is a broker involved, you will most likely be expected to make an offer first.
Agreed
Normally, for me and my friends at least;
1. Find said plane
2. Agree on a price for the plane in STATED condition.
3. FAA records CD obtained, verify title and go over all the airworthy related stuff, NTSB search run on tail number(s) and serial number, flightaware checked for current activity if it's not a blocked tail number, run the seller through the airmans records, Google search of the aircraft and seller.
3. If all still looks good.
Deposit sent after purchase contract is signed, I often use the AOPA purchase agreement template, with a few tweaks if needed
4. Prebuy to verify STATED condition, and verify all documents are present and accounted for.
5. Price may go down if differences are found between STATED CONDITION and ACTUAL CONDITION, or the seller just brings the plane back into stated condition before the sale closes.
6. If all goes well and is kosher to both parties, my prebuy turns into a annual if I pull the trigger, since my version of a prebuy goes above and beyond standard airworthiness stuff anyways.
7. Cash changes hands or accounts, 8050-1&2 completed, hands are shaken and planes are flown.