Torture doesn't actually have that much crit, not sure what you looked at, only 1 piece has crit on it, and 4piece bonus is an additional 110. Same with juggler.
IMO, the "cheapest" and best is the memento set, especially if you don't care about od. Of the 4 sets listed it has the highest available crit, and healpower. This is what my druid uses. I estimated juggler and memento heals but for priest, and they were equivalent, but again, cost efficiency and a loss in crit. I didn't do the estimate for druid, but since healpower helps druid (d/s especially) much more than it does priest, just a guess memento would still top.
You forgot VN which, just eyeballing, appears to be slightly better than torture, but I'm pretty sure this is the hardest to get.
Vahtos suffers from a lack of passives and plussing stats, and it has the lowest crit available. However, if it is a dpsing druid (umm are there any) then this is a much cheaper set than juggler.
Torture/juggler sets actually have a lot a decent amount of crit when you plus up the necklace. I believe the crit you receive is around 800 points when +16'd and od.
Vahtos should be replaced by either gch or tosh memento healing set when they are accessible to the player. 15% spell power is nice, losing out on all that crit is not. A happy medium is the juggler set. +10% spell power, and a good amount of crit.
Personally, Im avoiding the VN set. 8% wisdom, which is useless in terms of burst heals (would only affect regens be small amount) and 2% healing is nothing compared to the ZOMG crit and heal point bonus of the tosh healer memento set.