I'm not adverse to building several of a kit, I just work too slow to do so most of the time!
When I'm building something, different ideas keep going through my head. For instance as I was working on my '34 Ford that I did a slight section on, I got the idea for a much more radical section that's still going through my head. And I do own a second kit!
There's also the 'if I knew then what I know now' factor. The Heller '28 Citroen truck was a pain to build, but now with the experience behind me, I could do a much better job on the next one. So happens I have the woody pickup of the same kit, that I found the '34 Ford chassis slides right under! So a street rod version may not be far behind.