Obviously, I'm a fan of these old toys, and I'm guess that if you've read this far, you are, too. And now that you know my "secrets" for finding these, you should be able to find the old transformer toys for sale that you've been wanting - good luck!
Ebay. Some say the days of finding diamonds in the rough on eBay are long over, and I'd agree to a certain extent. Gone are the days when people would simply list their junk for basement bottom prices, because the site seems dominated by professional buyers/sellers who are well aware of what they have and the value of such items. I used to find classic transformer toys for sale at very low prices here, but now it usually costs more than Amazon. The upside is that there is always a huge supply, so you should be able to find what you want, just be prepared to bid against retro collectors with very deep pockets.
I have the following transformer movie toy for sale. This is an extra set that I used for display. It is from hasbro and it is hard to be found. It is brand new and not opened at all. Ideal for kids as a christmas present. The price will be as follow: -