i paid £20 for mine from a car show! £20 is about the lowest you can get one. mine sits on the tb like the k&n but doesnt have a breather pipe. but you can buy breather filters for £5, breather filters arn't that important tho. all filters do the same job if you want power go for a panel replacement filter (like the standrad one in a box) and if you want noise go for one like mine. i did have a small prob with mine tho.....the top sponge fell off 
heres a pic, you can slightly see the breather next to the standrad air feed pipe.
hope this helps a little.
