If you're building a commercial app that needs this kind of functionality then $490/seat is not expensive, it's the cost of a fairly cheap developer day. So ins

If you're building a commercial app that needs this kind of functionality then $490/seat is not expensive, it's the cost of a fairly cheap developer day. So instead of messing around for days trying to get various partially implemented open source/free "Excel" type grids to work, you pay your money and get the job done more quickly.