One of the models cast from the Phase II Enterprise parts sold on ebay a couple months ago for just over $15,000 (here
). It started at $3,000 but didn't stay that low for very long. It would have been interesting to see if it would be possible to restore it to the original Phase II specifications.
Looks possible, Most of the hull shapes are unaltered. You'd have to hack the extra bits off, replace the bridge, redo the torpedo deck, etc. It would be a lot of work, but perhaps less than building from scratch!