I'd like to know as well because I'm interested in replacing my third party leather loop. I bought it over a year ago for around $20. It shipped from Hong Kong. Looked fine and has been comfortable, but it hasn't held up very well. The "leather" is peeling a bit. It was fine for almost a year though, although I only wore it about half the time. I suspect most of the cheap leather loops are about the same.
Amazon doesn't seem to have as many as they used to. Lots more Milanese loop options, which I'm considering. Love the leather loop look though. My other third party band is a Clockwork Synergy leather band. It's much better quality and has held up well for a $35 band, but unfortunately they don't make leather loops.
Sean
I thought I would add that I decided to "repair" my leather loop for the third time and maybe this time my fix will last a little longer. When I said the "leather" (pretty sure it's just vinyl) is peeling, I mean that where it ends at the lugs there is a gap where the material is pulling away from the lug. I have carefully glued it down a couple of times. If it doesn't stay this time I'm going to replace it.
One thing to consider is that many of these bands ship from China, so returning a bad one will be slow and possibly cost more than it's worth for an inexpensive item. If you do decide to buy one, try to find out where it will ship from... and also where you would need to ship it back to... if you don't like it.