[Davol70]

Morning all.
I have a 2010 x5 40d (N57) which has been leaking oil for a while. It is really starting to get to me now, especially when it leaks on to the exhaust and smoke is bellowing out of the bonnet when sat at traffic lights! I was originally told it required a new rocker cover gasket which I had replaced by a garage, however still leaking pretty bad, mainly when driving above 2000 revs. If i drive like a nice respectable grandmother it's fine!
I have now been told it is most likely a warped or cracked valve cover. I bought one myself with the intention of fitting it but I think i have taken on too much.
My question is, will a garage charge me the same price as fitting just the gasket if I provide the cover?
Many thanks in advance for any replies.