Autovolks are free to charge whatever they wish for work carried out, and should also honour any warranty for work carried out.
I personally think it's expensive, but I am in a position where I can source cheap parts and labour.
I certainly wouldn't call Mintex, Monroe and Mann rubbish parts. In fact Mann actually make the oem filters for VAG.
It's always a good idea to shop around when it comes to this. Perhaps the OP shouldn't have named the garage as its a little unfair.
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