I purchased a "leather" passport cover in the '80s for about $20. It delaminated onto the passport. I currently have a Pacsafe Rdif passport wallet for $29. It is incredibly thin. If you google leather passport covers you'll find them as high $300. To a certain degree you get what you pay for. I do not consider $50 for a passport cover AND wallet too much.
The wallet functions here add a fair amount of time, and therefore cost, to the construction. We do offer a simple passport cover for $30 (retail) is that something you guys would like to see on massdrop?