There is at least 1 LoneStar prototype boat that I'm aware of, that might be pricey to try and buy, but rather then asking us to place a value on a boat, how about you tell us what the seller's asking, and where you and the seller are located.
The prototype I'm aware of is about a $5K boat, w/ motor and trailer, in reasonable condition for it's age, 50+yrs old. Because I can't afford it anyway, I don't really have an opinion on whether it's 'worth' 5K or not, but that was the asking amount, and what was paid.
BUT, in other parts of the country, 5K may seem like a bargain, esp to someone looking for odd, unusual, rare or prototype boats. Or seem exorbitant..
Just because it's a 1 of 1 known copy of a boat (extremely rare) it still may not command a high price, depending on exactly what it is, it's condition and what it'll take to get it back in the water. In the end, old boats are only worth what someone will pay. And that amount could vary greatly city to city/state to state......
And read thru this for help posting pix:
Photo Upload Tutorial
I look forward to seeing some pix of the prototype, and what the seller's asking for it.
BTW: Make sure you know the title and registration requirements for your state. Old boats often don't have titles, and many states can be difficult to deal w/ if there's no paper trail and clear documented ownership......