Over at http://www.1saleaday.com/ Time Ace is $7.99 with $4.99 shipping for the next 23 hours. This is probably about $4 less than most places; plus you factor in the no tax (well, for 49 states that is).
I played through it a few months ago. It's nothing spectacular, but at that price it's cheap enough to try out. It was good enough for a week of bus ride commutes.