Is there a save point before fighting Bonetail in the Pit of 100 Trials?

I've almost fully completed Paper Mario: The Thousand Year Door, with only the final optional boss fight with Bonetail to go.

However, he is at the bottom of the Pit of 100 Trials, which means you have to slog through 99 battles in order to get to him (more or less, as randomly you are able to skip a few levels). Regardless, I am not eager to spend all the time getting to Bonetail, only to lose to him, which would force me to repeat the entire process.

I've been down to level 50 of the Pit and have not found a single save box. Is there a save box right before the last level?

Nope - no saving is what makes the Pit so darn tricky.