I would almost garentee thats a chinese filter (based on the price).
while aftermarket gaskets are usually ok, (dont forget to change the spacers that are in the bolt holes from the old gasket to the new), I really prefer OEM Filters (meyle or mann) which is what I sell in my filter kit.
How often?? since vw doesn't give a service interval (which is bologna), this is simply opinion. Ask 10 folks youll get 10 answers, but 30,000 to 50,000 is what I would suggest.