I don't think that's it's a bad idea. It's kind of a good time to let ppl know what it's all about and if they decide to do it or not--totally up to them. Otherwise, if you have a PnP party--they may feel obligated to do it. But, I can see how some may be turned off by the $ part though.
At first I equated it with having a balloon guy but then realized I didn't like the idea of pp getting out their wallets at a party. I'll just have to do it separately. I think someone mentioned hosting one soon - I did it at 6 mos and now it'd be cute to do it at 1yr.
Re: Piggies and Paws at bday party?
It sounds like a cute idea.