No, none of those mechanical keyboards are "good". The closest thing you can get to an under $50 keyboard is a Striker RK 6000, made by Rosewill. It's good while it lasts, but it starts to fail after a little. I'd recommend not buying it and saving for a better one which will feel better and last longer. The Rosewill RK6000 uses ALPS switches, which are similar to blues. But Cherry MX blues feel a lot better, to me at least.
I have an RK6000 and it's beginning to fail me. But if you get it, get a warranty. I've had this board for half a year.
Mechanical keyboards under 60 are generally not good at all.