Hi. The cheapest I've found is $20.80 for 1,000 superworms including shipping. I've dealt with them a few times but I have had problems with them. I paid for my order of 8000 and only received part of it and they said they would credit the remaining to my next order when the weather warmed up. Four months later, they said that they were shipping and encouraged me to order and pay for more because of weather conditions and availability so I did. It has been six months and I have received nothing...no worms, no refund.
I've EM about 15 times and tried calling which they must have caller ID because they will only answer the phone when I call from someone else's phone and when they hear it's me, they hang up. In fact, the billing lady keeps telling me that I have the wrong number and yelled at me to stop calling.
So, Reptile City is the cheapest, but they are horrible about when and if they ever ship.