BA5T™ is a completely different alloy family than the BATT™ alloys (The old alloy, and the 2007 alloy), and has a different “Feel” when polishing.
These descriptions result from the lower Coefficient of Friction and different Fractal Dimension (Surface complexity of its microstructure) compared to other tin alloys, including BATT™.
These laps are intended for the experienced BATT™ user who requires a harder-finer-grained lap for HIGH SPEED PRODUCTION POLISHING processes.
The very complex alloy, having attendant casting quirks requires a heavy (“Pro-Weight”) 2.5 Kg casting, and extra machining steps. This of course allows more resurfacings for a longer service life.
For someone slaving under a stopwatch for a living, they are cheap, but the regular production “BATT™” will always remain the best Price/Performance value for the hobbyist.
BA5T™ contains silver and other cost drivers that make it impossible for it to be a cheap product.
Competition cutters want to win, some at any cost. They don’t care about a few Dollars. Commercial and Professional cutters know that “cutting tools” are fully tax-deductible and depreciated in one year. Cutting hundreds of stones a year, a BA5T will polish better and faster, and pay for itself quickly. So they don’t care what the BA5T™ costs at all..which is, in their case, arguably, “Nothing”.