It's $34.95 per adult (kids are included free). You have to get it for all adults on ressie. I just added it yesterday my final payment was due for FTP and we have 2 rooms at GF for 3 adults and 3 children and our total was $4400 so i figured the $104 was worth it in case something unforseen came up. I have 2 friends who in the last 2 months have lost lots of money on vacations when they each had a parent get seriously ill suddenly. Both had no insurance and said they would NEVER travel with out it again.
I would say it would depend on how much it would cost vs how much you are spending on your trip total. there actually was a post about a week or two ago where someone posted the fine print of the policy. I'll see if I can find it and post it here.