I'd pay that in a heartbeat if it had the API and UI that fits in with the rest of my software. Better an upfront price in dollars for a component that I know will be well-supported by a company than a "free" component that will likely be abandoned or mismanaged by one bored developer
With a disclaimer for me being employed at Bryntum (and the main author of the Grid component), I still think the chances of getting long term support are better with a paid component from a specialized vendor. Wether you buy Bryntum Grid or AG Grid, there are agreements and such plus the fact that the products are the livelihood of the devs behind them. For the really large vendors though, I guess some of their widgets are to "plug holes" and the mileage may vary...
I'd pay that in a heartbeat if it had the API and UI that fits in with the rest of my software. Better an upfront price in dollars for a component that I know will be well-supported by a company than a "free" component that will likely be abandoned or mismanaged by one bored developer