I move this over to the Subeta Pets forum. ^^

As stated you can still purchase slots from the Millionaire Center, you can get a total of 5 pricing at 20mil, 40mil, 60mil, 80mil and 100mil. The price increases with each slot you purchase.

You can also purchase slots from your pets page for CSC (Cash Shop Credits) at 2000 CSC a piece. CSC can be purchased directly from the Cash Shop through Stripe or Paypal, or you can purchase CSC from user shops with sp by buying Cash Shop Credit cards and redeeming them for the credits.