Lest I be understood to be down on kit building or buying planes, I'll add my 2 cents in to the recent trend in the thread also...
My real concern for those potential builders is that they know that they can financially finish the kit, and fly it a while. Once they get that far, one of two things will happen. They will A) find out they can't afford it as well as they thought, and slow their flying, or possibly sell their completed kit, or more likely B) they will prioritize their life a little more around their awesome machine and enjoy it. I don't want to see someone get in and fail at completing their kit, but if they truly have the income to build and support it, hey, the ride is far more awesome than they'd ever imagine.
My thoughts are like Wayne....get the family in the plane, and get out and see the world. I rarely fly for short local hops...that's not what an RV-10 was made for. If that were my flying style I'd have bought some other type of kit. The RV-10 is made to go places....and that's what I've been doing. I've now made it to 48 of the 50 states (Yes, I'm giving an honorary checkmark to Hawaii....I went there, brought a piece of the plane with me because sadly I just don't think flying to Hawaii is for me...and flew around the islands with that piece in hand) So I've got 2 more states to hit with the plane. My kids have been to 49 states, and so would the plane had I taken the time to land in Washington state. To me, bad economy be damned. Anything can happen to me at any time. I can lose my income, my limbs, or my life, but so long as my family survives, I'm giving them experiences that can't be taken away. Yeah, I'll be pretty sad if 20 years from now the kids tell their kids "back then we used to be able to fly airplanes around"....but, I think part of giving people the drive to succeed is giving them something to dream about succeeding FOR! I think we should be taking every non-pilot we can out for a trip, or a ride...using our planes to keep showing the world what *is* possible if someone puts their mind to it. It's too easy for them to be lulled into a passive lifestyle...and be happy as they are. By showing them there is more to life than work and TV, we're helping drive them, and drive the economy. So unless the cash in your bank account (or gold/silver) is cash you really can't afford to lose, a certain amount of life needs to be LIVED....and an airplane isn't the worst place to store your money. You may lose some or all of it, but you will be paid back many fold in experiences.
Back on the pre-building part of the thread...I should add about marriage: Make sure that your spouse has at least 50% of the love for the kit and what it will do for you as you do. A supportive spouse will be a tremendous asset, but a non-supportive or anti-supportive spouse will bring you disappointment even after you finish your kit if she's unwilling to use it with you. I'm pretty passionate about flying, and I'm thrilled my wife is. I honestly think if she wasn't, that push would come to shove and I'd replace my wife. <gulp> That's a tough pill to swallow, but if having an RV as a toy is going to do nothing but make your spouse angry, you are probably going to have enough friction that you'll have to choose one over the other some day anyway. Luckily finding someone with similar enjoyments was at the top of my list when I was wife shopping.
Anyway, if you finish an RV-10, and your family is on board with the whole deal, there is no way you'll be disappointed with your choice to build.