although as that card was never very popular with either gamers or miners your chances here are not great either. 
HD 5830 actually was actually quite popular among the miners, it usually had a good price:speed ratio, though there was less demand for it at times when the BTC price:difficulty ratio was getting worse because 5830 is a power hungry GPU.
You mean like few years back? I though HD 5850 and HD 5870 is much better in term of hash/price?
HD 5870 weren't usually that good in terms of speed/price but they were quite good in terms of speed/power draw, and using them meant savings on motherboards/RAM/CPU because there's a limited amount of free PCI-E slots on each motherboard.
I'm not saying it was always like that with 58xx GPUs, but in general it was how I described.
5830 were cheap but not so appealing when it meant they would take up more space and draw more power.
5870 were expensive but they would take up a lot less space.
5850 were a good balance between those two.