I used the Libsyn100 plan for a while before my podcast died.

It no longer seems to be available? Is there no tier between $5 and $12 with statistics anymore. It seems like a big jump in price for this of us teetering in the 100M/month usage levels.

Yes, we did do away with the 100mb plan for users who were not signed up for that service level at the time of our billing system update back in May.
If you had that plan going into the update, you were allowed to keep it at an increase of $1.
The lowest service level is now 50mb for $5/month. There is an option to add statistics for an additional $2 a month, bringing the total to $7 for 50mb w/ stats.

Please let us know if you have any other questions.