Possibly. I think there's more than this, however, because even Raymond's price is decreasing. Contributing factors as I see them:
1. Joycon Emulator "Piracy." I've not personally done this, and won't explain here how this is done, but it's not hard to do and becoming increasingly well-known in...
I can second this. I had a glitched Lucky whose plot was cleared after test-TTing forward one day. Not an ideal fix but a fix. Not proof that the glitch itself is definitively gone (it's possible, for example, that the glitch can still happen but the villager now simply disappears instead of...
Couple of suggestions (feel free to disagree, of course).
Ruby: B->A. She's very frequently posted in the discord with c/o of 30+ and b/o of around 50 (which are common price levels for other A-tiered villagers), and shows up occasionally as an LFT-request. I don't know how well she actually...