Windows Phone Thoughts: Software Impulse Purchase Pricing: What's Your Threshold?

In the retail world, there's something called an "impulse purchase" - these are the items of candy or little low-cost items located near the cash register in stores, where, when you see them, you just react by grabbing the item you want (gum, candy, etc.) without really thinking about whether or not you truly need it. So here's my question for you as it relates to Pocket PC software, because it's something I'm curious about. And for those keeping track, this was posted today in the Sunday time slot, so I'm reposting it at the correct date and time.