Hello and Welcome To BYC! You might post on your state thread for suggestions on where to get coops, there don't really seem to be any mail order coops that are inexpensive but well made https://www.backyardchickens.com/t/270925/find-your-states-thread also be sure to check out the Coops section, there are a lot of small coops members have made, many of them have detailed plans, also check out pallet coops, some of those are fairly simple and they are made from reclaimed/recycled wood.