The Jump Tonic now costs 200GP. I think if it's going to be that expensive, it should not only remove disease, but give immunity to disease for a period of time.

Jump Tonic is not the only solution to disease, there are a few other, much less expensive, methods to rid a character of illness. Just look around a bit.

Well yes, but even if there are cheaper alternatives, Jump Tonic should be worth something, rather then just another expensive, useless item.

I'd rather people weren't in the position to re-sell Jump Tonic for a profit to other NPCs (as they could do before). Short of making it buyable through a scripted dialogue instead of a store, that's the lowest it can be because of bioware pricing.

And 200 seems reasonable, especially given it cures ability damage.