I'd be shocked if the seller would accept $350. That's less than I paid for my 3" 624 back when they were new.
You never know till you ask. Also putting a little guilt on them about the recall can't hurt.
Here's a war story from my work. We needed to try a specialized video converter. It changes video signals, RGBHV into YUV.
Hang in there, I know this is highly technical but the nerd readers are getting excited. Retail these little black boxes (blue actually) go for $300 plus. I saw a guy on eBay with over 15 of them he'd pulled out of an installation. He wanted somewhere around $50 apiece for them. Reasonable. But I offered him $15..............for a pair! He accepted. I think he had so many he was happy to get anything for them. And since it was a private transaction, other buyers on eBay didn't know how low he'd go. Both worked well, btw.
So you never know.