If you can't afford $300 for your kids, you have big problems. You are certainly not the family shown in the advertizement. Also you need a keyboard and monitor which could easily set you back another $100. It is my humble opinion that the price differences between this and a real computer are unjustified, just buy your kids a real pc!
believe me, I know plenty of people who wish they could afford half of that for their kids. with that said, the threshold of an affordable 'household pc' IMO plateaued years ago with a 4GB 2.5Ghz system, if that. if you look around, you can find an old system to revive for less than $100, and you can get a standard mouse/keyboard for 20 bucks.
Yep, your living like a lot of people on the edge. You cover your bills and clothes and then don't do much else. I am truly disappointed that the opportunities I had to learn to program in the late-70's and early-80's are not there anymore. We have cut off a part of the population from learning to program early even though the price of computing has dropped.