How many vertices per second can the average graphics card push? [closed]

"What exactly would vertices per second measure? You leave out too many variables.
What would you use the metric for? As a sane default or upper bound for your application's draw calls? For benchmarking? If so, you probably want to benchmark fill rate and triangle draw rate instead. See my post regarding this here: stackoverflow.com/questions/1493581/how-to-go-about-benchmarking-a-software-rasterizer/1504635#1504635

On the other hand, if I take your question literally, I sadly don't know of any trustable sources for low-end graphics hardware performance. You surely don't want to trust the vendors themselves. I know of a good usage survey though, and that's the monthly Steam hardware survey: http://store.steampowered.com/hwsurvey/

Since I'm not aware of any sites with good and deterministic benchmarks statistics, knowing which cards (and technology) is popular is the second best thing, if you need some statistics to help you make correct choices for your target group."