Stability is all relative, what camera are you using? For that budget though, I guess a Slik U8000 is your best bet.. or maybe some Velbon (though I dunno if there's a decent one at $50).
What they mean is that the head cannot be changed to a ball head. It has a quick release mounting shoe (normal type that you seen on pan head tripod).
I 'm willing to let this tripod go at $45 - it has been used only for 3 months - bought in US. Will be replacing the mounting shoe to a new one if you want to take the deal.