Dwight:
I looked into those when I wanted to have a few fish cages. It was less expensive for me to buy a 4' wide roll of mesh netting from Stoney Creek and make my own cages, but I picked up the netting, no shipping..... For only one cage it would have been cheaper to buy the pre-made cages, but for 2 or more making my own was more cost effective. I made my cages 4' square, but found that if the cage was only in 2 1/2' to 3' of water, LMB that were held in the cage (13"-16" long fish) would get their chins scraped up on the netting. There has to be a recommendation somewhere on the 'net for cage size vs. fish size/density to minimize stress/trauma to the caged fish.
Either route you take, don't forget to fab lids for them - fish jump and birds/mammals can get in from the top too.
I forgot. If you do go with the pre-made cages, and you plan on using them for more than once, get them treated with the net dip. I've used the green dip and it's held up very well.
Last edited by esshup; 06/29/11 10:18 AM. Reason: dip