sell down

I have a bridge to sell you

An indirect way of expressing that the addressee is gullible.

sell bargains

To make saucy (usually indiscreet) comments; to come onto.

sell dearly

To make one's opponent pay a very high price to defeat or obtain (a person, unit, vehicle, or territory).

sell down the river

To betray, especially in a manner which causes serious difficulty for the one betrayed.

sell ice to Eskimos

To persuade people to go against their best interests or to accept something unnecessary or preposterous.

sell like hot cakes

To be sold in large numbers quickly.

sell one's birthright for a mess of pottage

To make an unfavorable exchange, especially of something of great, but deferred value, for something of very low, but immediate value.

sell one's life dearly

To do great injury to the enemy before being killed by them.