I am usually willing to pay a premium for electronics with compactness, simplicity, and usage of common batteries. However the XPal's lack of ability to send/receive text messages kills the deal for me. In emergencies its vital for a phone to be able to text. This is not hypothetical, it has been proven for real and discussed here on the forums.
If someone came up with an inexpensive phone (say, $50) that ran on AA Lithium batteries and had text messaging capacity, I'd buy at least a couple for our kits. Ideally you'd be able to buy a pack of minutes and text messages that didn't expire more often than once per year.
The pay-as-you-go phones I've seen have minutes and messages expire after three months or less. That makes them uneconomical for my uses. Even then I might buy one and be willing to activate it over the air (by calling customer service with a credit card) but the SIM stops working a few months after the minutes and messages expire, so again it doesn't make sense for my purposes.