This statement is going to be so obvious, it shouldn't really need making, but just in case anyone hasn't thought of it yet (and with sincere apologies to those who will quite rightly view this as teaching granny to suck eggs), trading any item for another, whether those items are common, uncommon, rare or mega-rare, is entirely dependent on both parties wanting what the other is offering.
I do not own a Palitoy 30 back Boba Fett, but would like to. If I own a one-of-a-kind, incredibly valuable GI Joe figure worth far more than Mr Fett (which I don't, but if I did...) and I offer to trade it with someone who has a 30 back Boba Fett, unless that person wants the GI Joe figure more than their Boba Fett, they're not going to trade with me. If instead, I offer an entire set of Palitoy 12 and 20 backs, including vinyl Jawa and large head Han, plus a dozen other mint 30 backs (which again, sadly I don't have, but if I did...), once again, unless the owner of the Boba Fett wants those other figures more than their Fett, they ain't parting with it (and let's face it, they're not going to find another one very quickly if they did part with it).
Sometimes it's not about the rarity of what you're offering or even the value of it. If the person with the thing that you want doesn't wish to part with it, then you won't get it.
Wreck-It Ralph, from your posts in this and other threads (e.g. viewtopic.php?f=1&t=34213&start=30
), with respect, you do not sound like the most patient person in the world, and instead (rightly or wrongly) come across as wanting to have everything right now. You are clearly very wealthy indeed (or have ready access to large funds) and hence have a lot of buying power, which certainly works for buying items available in the marketplace. The tone and nature of your recent posts however suggests strongly that you may feel you have exhausted all of the easy options when it comes to buying rarities quickly, and are now scouring about for other means of getting what you still desire. If you stick at it and are willing to be patient (and we could easily be talking about waiting for many years, in some cases, not just a few short weeks or months), cultivate good relationships with other collectors, develop a good reputation and don't piss people off, I daresay you'll probably manage to acquire some more of the things that you still want. If you're not willing or are unable to do that, then you probably won't. However some items are so rare and so desirable than you may very well never own them, no matter how much money you have and no matter what you do to try to acquire them.
There's a life lesson for us all here. We don't always get what we want.