Ask the shop if they will do you a better deal if you buy 6 or more. Most shops should give you a discount if you order in and buy 6, 8 or 10 of an unusual or expensive fish.
Find out when the fish are coming in and wait at the shop for the fish to get there. Get the shop to open the bags and put some fresh oxygen in the bags, then take the fish home.
Do not let the shop put the fish in their tanks and then catch them out a day or two later for you. This will add stress to the fish. If you can't get to the shop and take them straight out of the box they arrived in, leave them at the shop for 2 weeks and then pick them up.
Ask the shop to contact their suppliers and find out what the pH, GH and KH of the supplier's water is. Match your tank water to that so there is less shock to the fish.
Get the suppliers to send the fish over with one fish per bag so there is less chance of the fish damaging each other in the bags. They might already do this but ask anyway.
Make sure any fish that don't look perfect when you get them out of the box, is photographed and noted by the shop, just in case it dies.
