The idea that you have to buy MB over priced stuff is nonsense.
This was not my suggestion.
However, if one failed after 2 months, I would sure as heck investigate a bit further before investing the time and effort into changing the gasket with the same source as one that failed. Granted it isn't a fair comparison, but the gasket that did come with my Laso water pump was just a thin piece of paper. The MB OEM gasket was substantial; a
gasket. It was hardly expensive, a few dollars--but anyone could see the difference. It just makes some sense here to investigate what you are getting prior to installation.
Since you have to take the head off to change the gasket might be worthwhile to see that the head isn't warped and the surfaces are flat to spec, and nothing else in your field of view here needs to be changed.