I don't mean to open up an old thread, I just noticed there were some questions that went unanswered and wanted to make this thread complete as it was the first thread to show up in Google.
A good ratio to buy for these Dubia roaches are 3:1 (3 females to 1 male). Telling the gender is also very easy. The males have wings and the females don't.
The starting cost is very minimal. I would say less than $50. Most of the supplies you can either get for free or around the house with the exception of the water crystals(some people don't use these), and egg crates/egg flats. I highly recommend this YouTube video as a good guide.
Also, if you enjoy raising these critters to feed your girls and boys, you can also look into starting a small raised bed garden and grow all your dog, chicken, and roach food from it. Just an idea. Cheers.
Edited by worldinatunnel - 4/6/14 at 8:36am