I've been working on mine a long time, and for the right price, it's history.
Like someone said, building it is half the fun, and if you could do it all over again, there's so many things you could have done right the first time that you botched.
Hindsight is 20/20. Then again, I'd have to probably get $15k for my rig, rolled, bashed, and hacked at it sits right now, but if I knew then what I knew now, I could build an awesome rig for half what I have in mine!