I have some dog lines I want to sell all 3 have close to 100k points, but I have no Idea what to price them at! As I am still new to this game and don`t know how pricing works here. So if anyone can help me with that, that would be great!! Thanks!

Your best bet is to put them up for private sale, with a price of 1 HPD. That means people have to bid if they want the dogs, and you just need to advertise them. If no one bids, then you could just delete them? The thing is, I'm guessing these are store dogs you just bought, and people don't usually go for a 3 year-old dog with 100k points because they can do that by themselves with one week of training. Don't feel bad if these don't sell, though :)