It's too hard for me to explain you, I speak english very bad. But a friend of mine did a great post about it here : http://jul.rustedlogic.net/thread.php?id=12091&page=12
Why not release it on your own website and enjoy the notoriety of being the person who finally leaked it and solved the mystery once and for all? Why hold it hostage? Or why not just sell copies of the ROM on a per-person basis?
Honestly, after reading the post in this link, as much as I love Bloodlines, I can't understand why someone would ask for that much money to release something that, when all's said and done, is hardly worth the price. Especially considering the fact that you can't really even finish the game because of the bugs and lack of collision detection in some parts. I get that you invested a lot in that, but at the same time, doing so for the purpose of basically saying, "Na na na na na, I have this and you don't" until you get a certain amount of money, sucks. It would be one thing if you were asking for enough to cover the costs of hosting a site to download it or something like that, but asking for an exorbitant amount like $1500 is crazy talk imo.
EDIT: It seems like you've been trying to sell this for a few months considering you mention it in your introductory post over at the French CV forum, and that was posted back in September.