This happens to me all the time! I get super excited and then that stabbing feeling hits me in the gut
Before I began getting the occasional bonus at my job, and really began looking at where my leisure money was going, this was me literally almost every time I saw a toy. Now I'm thankfully a little better off... but sometimes it's still quite hard to look at some of the pricier stuff and say "N-no, I think I can wait..." and feel that pain given a lot of it is exclusives.
If on eBay, I put it on my Watch List………same with Amazon. If BBTS, Walmart, TRU, K Mart, Target, I take note of it, add it to my Amazon wish list thru my phone
I usually only look for things like that when I know I have the extra budget to do so. I also like to build up a hobby slush fund for just such "emergencies." Sometimes a truly good deal just cannot wait.