That GPU and Radeon 7990, are actually limited production GPUs. They are rare and hold decent value. If yours is in mint shape you should hold it for another year or so and some collector will buy it on eBay. Currently the 7990 is going for $200 or so. Which makes no sense since its basically 2 of the Radeon 7970 (R9 280X) gpus which an overclocked RX 480 can pretty much beat.
The rest of those GPUs however are nothing special and you won't get much coin out of them.
as did I mine btc with my my 6990
how crazy hd5830 could mine 1BTC a day.
Used to be able to mine BTC using any desktop cpu....nothing special....