I was a "gotta buy new" kind of guy. Then I got the bug to get out on the water, and knew that wasn't gonna happen in a new boat. Once I got over that, I've been happy. Not necessarily right at this moment (engine issues) but most of the time.
The big thing to understand is that EVERY boat needs maintenance. Yes, a new boat will come with a warranty for some of the stuff. But what happens when you're nowhere near an authorized dealer/service facility? As my step-father put it (he owned several powerboats when I was a kid, and is largely responsible for my enjoyment of boating), if you're lucky, a new boat buys you about 2 years, then you're doing the same maintenance as everyone else. You have to calculate the ROI on that, and decide if its worth it to you. If you heed the wise advice above and buy the boat a year in advance to practice on it and mold it to your liking, you're only going to have 1 year's worth of "maintenance free" time left. Personally, I think it's better (and again, this is just my opinion) to go with a new-ish boat that you can afford, and spend the time/money fixing that up the way you want it. In the end, your out-of-pocket costs may be significantly less, and you'll have a boat that's set up the way you want, not the way the builder thought it should be set up, with a few additions by you.
Something to keep in mind - we all are pulling for you, and many of us are jealous! You have your reasons for wanting to do what you want to do; we're offering different points of view as a sanity check, or a way of achieving your goal even faster, should you so desire.