Big jobs like full convexing a saber grind large Busse can eat up some belts. While Lee Valley has some good ones, I found an outfit in Texas that makes their own belts and sells them at good prices. This has saved me some money lately, and I am quite pleased with the quality. Check these guys out, Andy.
Be sure to check out their Blue Zirconia belts in the courser grits when you need to reprofile or remove a lot of stock fast and cool.

https://www.econabrasives.com/products.php?id=205&size=1x42