They can be found used singly for $23. I bought 4 of the GDDR3’s for $17 ea. recently (with shipping included and both full and low profile brackets supplied!), but am intrigued that maybe there’s a GDDR5 version.
I do graphics engineering as a profession, and typically get the latest workstation card under $3k. I’ll do this every 5 years.
Evaluating performance is not an easy task. Host capabilities and performance can give the best cards the worst experience. Ultimately, your apps matter most — are you gaming, are you crunching numbers, are you doing graphics...
I get the sense you’re talking about low-risk expenditures, and you’re interested in some technical guidance. While I know a lot about my profession, I can’t keep up with technical specs and capabilities of the h/w. If you’re spending less than $100, I wouldn’t worry about making a potentially bad purchase.
Good luck!