My dove grey manual set cost me 200 in reasonably good condition including door cards, rear headrests and center console.

There are some sets that are factory fresh and will warrant a premium, other's will be from difficult sellers claiming them to be 'mint' when they are anything but.
Rare seat options such as hurricane fabric, individual trim piping, factory modena leather, suede with leather bolsters, electric adjustment, heated pads or adjustable lumbar support will add to the price if the seller knows how rare they are.
I'm fairly certain that mine are as base level as leather vaders get.