I got a used tent a while back. I don't use it except once or twice a month, but I've had it for 4-5 years now. The inside is lined with smooth cloth and not just raw lightproof rubber stuff, no flaking like what you describe is possible in the working space. The arm hole sphincters are still strong, years later. The exterior silver is prone to acquire tiny flaws over the years, but nothing to compromise the lightproofing.
Using a tent is a dream for loading 4x5 and the bulky Jobo reels and tanks, and the larger tent size is comfortable with even the large Jobo 3010.
It does come down to a business decision: it may be worth it to simply buy new, cheap bags on a schedule, or the up front cost for the working convenience of a tent may make that choice worthwhile.