You can go to Infinitediscs.com and click on Star Destroyers to see the entire inventory that they currently have up for sale. And, at the top of the window there will be a number that shows how many discs there are. Right now, there are 506 Star Destroyers. That number was above 700 at times lately, and it has fluctuated between low 400s and high 600s for two days now. Infinite has restocked Star Destroyers at least twice since Innova's announcement (or, maybe just continuously since then).
I am not privy to the exact numbers. But, based on watching the numbers change I think each line represents 100-150 discs. So, more than 300 discs; probably more like 500. In one day.