I'm willing to give Amsoil a shot, considering the positive word of mouth that I have seen not only here but also heard first hand in the non-internets world. Considering the interval that I run oil (which I have honestly never had an issue with), a better oil will serve me...um...better.
As for cost, I consider it relatively irrelevant. Even at $10 a quart and $12 a filter, that (minus shipping, etc.) only adds up to a total of $84 for 10,000 miles of protection for my OCI. That's less only $,084 per mile for piece of mind. I can't beat that by enough to justify something cheaper. A $30 Jiffy Lube change at 3k miles would be technically $100 for the same mileage period, with crappier oil, an additional oil change (inconvenience), and so on.
As for the 'it's just a FORD FOCUS'-maybe yours is 'just a FORD FOCUS'. I may not be driving a Bentley to work, but my Focus is still a nearly $30k msrp work car. Considering that this car has the potential to be the last 'work' car I need to buy for a very long time, I will probably take care of it. I would rather spend a couple of bucks now for peace of mind and longevity. Don't diss my ride just because you bought a cheap version. I can assure you, my car is nice enough for me to take care of. To each his own.
FocusFest 2013: Best of Show
Gateway FFW: Show Class Outstanding
September '13 ROTM
Hatch Nation #161