Eagle90
I'd say for me it is price. But then again, if kit prices dropped, I'd probably get even more stupid on buying!
Second would be subject. I find myself wanting the out of the ordinary subjects. Aircraft you don't see much of, German WW II idea aircraft, armor that is not your main stream stuff (I really like the German 234 and all its variants!).
Eagle,
Thank you for bring this topic up. Years ago (back when we still had plenty of Newsgroups on a variety of topics) this topic came up and there were a number of modelers who thought that it was "wrong" to build a model of what they called "what if" hardware by say WWII Germans. I forget all of the reasons that some of them gave for why this was "wrong," even when it was pointed out to them that most of the modelers building these so called "what if" models were just building hardware that had reached the blueprint/prototype stage.
Those that built them pointed out that building a model of hardware that made not only the planning but blueprint /prototype stage was not building a "what if" model. And that in doing so it's no different then building a model of any of the hardware that say the WWII Germans were using such as tanks, planes, rockets/missiles, etc.
And that it is VERY different from building a so called "what if" model. I would say that looking at a model of a piece of hardware that was used on the battlefield and "evolving" it isn't "wrong" as I am sure that there are plenty of engineers out there who have looked at what was used on the battlefield by everyone and "improved" upon it and that as with a lot of U.S. tech there is a LOT of it of WWII German tech that is still being used somewhere in the world, and/or evolving and being improved upon.
So what is the general opinion here regarding the building of "non-mainstream" models?