I didn't go that cheap route.. I got all the items needed as cheaply as I could though.. Does that count? LOL
I went the tank way rather than the tub way- but I purchased short sided big tubs to place my 32oz clear cups into (with water + heater to keep them all warm).. that was the only "cheap" way I went with my set up.
I said $600, but was way off - looked at my files and all in all (not counting shipping packaging items, etc) I spent $600+ on everything not including tanks + fish.. tanks (for one breeding and one grow out) it equals up to $800-$900 total to start.
Money isn't an object for my breeding, otherwise I would of been going as cheap as I can and nothing wrong with that! I personally would rather be able to see my fry growing and being able to look for deformities easier, which to me is easier to see in tanks.
Good thing you don't need heaters :) It's winter here, snow will be coming soon.. I have no choice but to use heaters and such for mine :(
I wish you luck! You got some great advice from indjo and OFL, indjo has been wonderful in helping me with my coloring genetics for my breeding :)