If you end up with more chicks than you need, you can often sell them to feed stores.
Purchasing by mail order is the best way to get healthy chicks and a greater variety of breeds than local feed stores usually offer. But you have to order a minimum of 25 chicks so they can keep each other warm during shipping, and this often is more birds than most people want.
I found a solution to this 'minimum 25 chicks' problem. These same feed stores may be willing to buy the chicks you don't want. You won't get full price, but your neighbors will have access to new and unusual breeds. I only got 50 cents each, but at least I got a little of my investment back and the birds found homes.