I know you can do what you want.......BUT

We have not paid more than 50% of what the seller was asking except for one.
That seller was a young guy who was basically forced (nagged I'd bet:D) into selling his project because they were having another kid and he needed the money at the time.
We ended up giving him his full asking price which was totally fair and never regretted it.
I also stay in contact with him and have been sending him updates and pictures as things progressed over the years, and I promised him if we ever sold it he would get first choice.
Sometime before long we are going to meet up in person again and he's going to get to drive the car as it is now.(WAY different than when I bought it)