A wise decision.
I have somewhere my original spreadsheets with costings for tools, fittings and materials. Is frightening the number of tools you need and the combined cost of them. Remember you would be taking on multiple trades. One example I recall is my surprise that the cost of the main line out was double the original projection when you costed in the varnish, stains, screws, brushes etc etc.
The other significant problem, alluded to by Jen In Wellies, is that to cut and prepare a single sheet of wood the process often involves moving around all sorts of gubbins inside the boat this can simply be just to access the stock, in addition you need to clear the area you are fitting out, befor you even do that you need to ensure that you have clear passage to any tools and materials you may need. You then have to decide where you are going to cut the sheet inside or out, inside may be necessary but you will regret that decision later, outside is a hassle for various reasons.
It's not simple but it is very rewarding and also you have all the tools you'll need for future maintenance, unfortunately you have limited space to keep them on-board.