It's quite difficult to generate a block right now. If you've got lots of other things running, then from a practical perspective I think it would be better to get not generate bitcoins. My guess is that it's not so much the process priority that's the problem as much as just the processor thrashing between tasks because it's got so much going on. The more tasks you have running concurrently, the more important it is to leave a portion of your total CPU below the maximum in order to keep your system running smoothly.

If you've got a specialty, you could offer your services in the Marketplace section or if you've got unwanted electronics or other item, you could offer to sale it. Trading for or buying bitcoins is probably easier, faster and cheaper than generating them on your computer.