I've never run out of thanks either, I don't even know what the limit is. I feel like I thank enough already without needing more. Maybe others are just more easily impressed than I am :p
Having said that, I don't see the harm in raising it. I doubt it'll be abused that much (if at all). It's not like we all have thank counters visible on every post so there's not going to be any obvious elitism or anything.