MakerBot Print is our newest print-prepration software, which supports native CAD files and STL assemblies,
allows you to interact with all your printers via the Cloud, and many other exciting new features.
I found mine on eBay: https://www.ebay.com/itm/361813670877
This is the cheapest that I found where I didn't need to cut it myself.
Just ordered 2 sheets and provided my measurements.
Came out to around $55 shipped.