[CalebD]

The hull is solid but where one of the supports it rests on there is an indentation into the hull. The guy says that that will pop back out when it's pulled off. Is that true?

It is likely that any indentations will pop back out after a short while in the water.

Is this boat too much for a novice craftsman with a low budget?

That depends on how much it is going to cost you on an annual ongoing basis. The price of the boat is just the entry fee before summer and winter storage costs. Where do you intend to keep the boat in the summer and winter seasons?
Keeping a boat about that size at a boatyard just for the winter in my area costs about $1k/year. Having a working trailer for a boat can save you a lot if you have your own yard space.

If you can afford the ongoing fees then you can afford to buy the boat and put a little time & money into it.

By the way, $900 is not a fantastic deal for this boat considering it is missing a jib, an outboard motor and has fiberglass damage in the cockpit. You could spend $2K for a new jib & outboard which might be a good price for this boat IF it was in very good condition.