I'm a sucker for redecos (whether they're exclusive or not) so IMO, if it's something that interests me, I will pay the asking price for it.

They don't necessarily have to be limited run Botcon or TFCC exclusives, I am even prepared to pay a premium to get some of the Japan redeco releases (e-Hobby, etc).

One of the examples you list (Cheetor) is of no interest to me whatsoever, so in this case, IMO this particular figure would not be worth it.

Whereas other people may think G2 Sideswipe's a complete waste of money, yet I think he's worth the price.

I guess it's all relative to your collecting habits and personal taste (and bank balance!)