;D Well the "exception" would be an MR Obi TPM. But I'm pretty sure I'm dreamin on that one. So, I would go for something Qui-gonish, maybe an Obi "arena" hilt that would be out there (dig those big time ;)).
Along those lines. Really what it would come to for me is trading "good work" for "good work". Meaning I would really like to trade someone who has a custom set up of their own they are looking to sell. Keeps it fair, keeps both hilts in the "saber community" and to me seems to be a benifit to both parties. If I can't sell the starkiller, then I don't see any harm in trading it to someone who has done the same as me in building a hilt ;)
Kinda a "lightsaber exchange" program LOL ;D
You get the idea ;)