If I sell for too low a price on the Steam marketplace?

Right now you can buy a TF2 key for $2.42 or sell for $2.38.

Let's say that I enter a transaction to sell my key at $2.40, and it's on hold for 15 days.

But when the 15 days are up, the price is higher: you can buy for $2.75 or sell for $2.70.

Do I get $2.70 (minus fees)? Is the marketplace smart enough to handle this properly instead of selling for $2.40?