Oil filter to engine block gasket

I have about 52000 miles on my x3 and BMW told me I have a leak from a gasket between the oil filter tube and the engine block. Total cost 700$. My question to you guys is: Is it ok to go with a local mechanic that claims to know some stuff about BMW's or should I definitely go with the BMW dealer? Is this that hard to fix? Can you get the part from BMW directly? Thanks so much for your input.

Bump?