Buying a glob of ectoplasm, the last time I looked, cost around 35 silver.
Selling a rare item seems to average around 30 silver.
But you don't always get ecto from salvaging a rare. Or sometimes you get two. Are there any stats showing the average rate at which ectoplasm drops from salvaging rares? If you need ecto, is it better to salvage your rares or sell them and just buy the ectoplasm?