Doesn't seem worth it to me. If you're cool with the Hasbro one, great. If you want an upgrade though, just buy the SS one. You can almost always get $20 off with a coupon. You could sell the Hasbro for $10-$15 and part out the SS stuff you may not want to recoup some funds and end up paying close to nothing. The Exclusive unhatted head, bespin coat, shirt, and stand could go and not impact the display as you currently have your Hasbro. With what you are looking at to upgrade, those things will be darn near $100 anyway. Not as much if you don't do the head, but if you do, you'll need to mod the heck out of a crappy Hasbro body or get that new too.
It's more work this way, but spending $90-$100 to upgrade a $15 fig doesn't really make sense.