Does this happen to you all the time?

My Dad was hauling my car to Texas from Atlanta and got a very serious offer of 15k, guy said he could be back with the cash in 20 minutes...
My Dad still jokes about telling me my car fell off the trailer.
I used to always say "Not for sale." , until my buddy told me to just give them a very lucrative number. From now on I'll just add 10k to what I have in it, lol. If they bite, I'll find another one.