I certainly don't buy toys with the expectation that at some point I will be selling it. I do understand there are some people who will buy a toy, experience it and then sell it once they are happy they got to have that experience.
What I don't get is the 'hey guys please buy all this stuff I don't want to sell because I have a Dentist bill I need to pay for' mentality. I get that it's hard to pass up on stuff you'd like to buy but if you're living that close to the line perhaps you should reconsider. (I saw this in the last week)
I get that sometimes unexpected expenses come up but a single even if big bill shouldn't be putting you in the red.
I've always tried to be selective with what I purchase, knowing that more and more stuff is always going to keep coming out and if I don't like 'this' version of a toy/character just wait a while and there will be another version that I might prefer.
@Seraphim Prime, I know exactly what you mean. I wasn't going to buy into animated, then I went to the 2011 Botcon, now I have pretty much the entire animated toy line. I was also only going to dabble in the latest RID but here I am and I have pretty much every warrior class toy that's been released and the platinum grimlock & Bumblebee set. I do enjoy them though, so I guess it's money well spent, to a point.
I also buy a lot of CD's and Trade paperbacks and other books. I listen to music all the time and probably could stream a lot but there is something special about having your copy of something that you like. My Phantom comic collection is pretty much up to date but I'm nearly 3 years behind reading them simply because of the lack of time lately.
Both of my parents have been collectors of sorts over the years, neither throwing stuff out in case they needed it. so I have a horrible pedigree when it comes to keeping things I might not need. I'm very soon going to have to do a serious box cull. The problem I have, especially with Masterpiece, platinum, Hasbro/Takara special releases and 3rd party is so much of this stuff comes in stunning boxes and it feels like a real crime to throw away the pretty artwork. But at the same time, I'm never going to have enough space to display all that stuff so why keep boxes that are by far the biggest volume sink of a transformers collection.
back to the topic at hand, I buy a lot of transformers and related products and try to avoid buying stuff that i'll not want to keep later. I do find I will buy toys in a line with the expectation that they aren't great, just to see how they work. Crash combiners are a perfect example. They are a bit rubbish but the engineering is interesting. I bought one pair. Lets just say if the kids break this one in a couple years when they're big enough to play with it, I won't be devastated.