We used to offer a $10 plan but we found the margins were very low. $25 allows us to provide great support and very few users need more than the limits on the plan.
Line2 is $15/mo and it offers a pretty good service including desktop clients. Oh, did I mention they offer unlimited calls and texts? I'm using it for business - I ported my toll-free number to Line2 and I get unlimited calls and texts (!) with toll-free number. Yes, you read this correctly - I can text from my toll-free number and I can receive texts, too. The only thing they suck at is offering an API.
