spot is $100 a year for basic service, unlimited predefined messages I believe, includes no tracking
inreach is $120 a year for basic service, includes 10 messages (custom or predefined) per month (1.50 each additional), track points are 25 cents each
Both have add on plans to increase features or messages.
I opted for the basic inreach service since I rarely use tracking or more than 10 messages a month. This summer I was on the trail for a month and ran my bill up to around $30 testing all of the features to see how the system worked (posting to facebook, sending track points, and 2 way texting). For me, the extra $20 per year is worth it just for the ability to send/receive text messages. Pretty nice in the event of a break down or real life emergency. Just don't let your kids use it unless you have an unlimited plan