If you sent a deposit to the seller and you made the effort to inspect the aircraft, you should get to fly the aircraft. Don’t let the seller tell you, “there is no need to fly aircraft, they all fly the same”.
Never buy an aircraft without flying it first!
Do you buy clothing, shoes or cars without trying them out first? You should apply the same consumer logic to an aviation transaction. If you can return the aircraft after you buy it, then your risk is reduced if you buy it without inspecting and flying it. But you usually don’t have that option.
Some reasons a seller may not want you to fly it first is; because it doesn’t have insurance on it, something is not functioning properly (not airworthy), it is out of annual and/or the owner isn’t current or qualified to fly.
If the seller won’t let you fly it before you buy it, how do you know it will fly home? You may not be able to fly as Pilot in Command due to the seller’s insurance policy but that shouldn’t prohibit you from being in the right seat. Single place aircraft raise another issue; you can’t fly with the seller.
Before you send a deposit or set out to inspect the aircraft, you should ask about test flying the aircraft and be cautious if you can’t ride or fly before you buy.