@Valtien
A daily (or weekly) trade in is a nice idea. You would have to consider the effect it would have on the pixpet auctions/sales which would also be greatly effected by this. There would be less eggs up for auction for example as people will be hoarding their eggs in hopes that they can be used for this. The drop in auction pets could effect prices, as the prices are likely to go up, especially if the egg is wanted in the trade for that day.

I would be looking at the current auctions and ask , do the prices seem low right now? Could an increase in prices be good, or bad? If most of the pros and cons point towards an increase in prices would work, then maybe this new feature would be a nice addition