The unfortunate usage for numbers for both tiers and item star levels (...and then item heat levels, but let's not get there yet) seems to leave a lot of people confused, or at least hamper with communications -- I have a tier 3 item now! No, it's just 3 stars. But tier 2 was 2 stars! No, that was a coincidence.
Granted, this is a minor trip-up, but it shouldn't have to be something people have to point out for you, and the game should at least strive to not deliver the crushing disappointment of thinking you're about to enter the next tier and finding out that, no, you are at best halfway there. Have fun.
So why not letters? Tiers A, B, and C. You can even put C in ornate, scary lettering. This isn't entirely a bad idea is it?
To be fair, it's stated pretty clearly that tier 2 is 2* and 3*, and tier 3 is 4* and 5*. Players not knowing better simply did not read. But I agree, it trips MANY people up. If a simple solution can be found, I'll sign.