How low will blue h'weens and eggs fall?

With rares, they will ALWAYS rise. Even if currently they are dropping they will surely rise, due to their are discontinued. It's not like an armadyl godsword you can get everyday, a rare is exactly that. A rare. So yeah, I'd keep them for a few months / years even if it seems as though the price is lowering. I'm sure it will go back up, wait, I'm positive it will rise.