Agreed! I was able to track one down (at least I think): https://www.alibaba.com/product-detail/31-5-e-ink-13-3_16013...

A bit more expensive than the one I linked previously at $1,400, though it's a full color display. It's unfortunately missing a description, so the only evidence that it's a touch screen is in the title itself. Would obviously require some due diligence with the manufacturer.

I'm sure there are other options as well (the breadth of vendors on Alibaba is pretty impressive actually)