User Review: Sea to Summit 100% Premium Silk Liner
Price Paid: $10
This is the first liner I've used, and the only. It's awesome for hot, muggy days on the coast, as well as cool nights inland. Alone, it's comfortable from 70F+, and it's a great way to keep the bag clean.
I would not spend more than $25 on this however, unless you are an ultralight freak that will carry this in your pocket as you run the Gulf Coast.