I can only suggest a BR or "ceiling" that one is comfortable with.
Personally, from what I have seen in all my test data shoes, 160 Units was the highest bet/LTD level I needed to make to recover my losses basically.
I did bust on a couple other shoes but, was not willing to go any higher and just called it a loss. I could have continued to throw money at those shoes and eventually won. It's all up to you and how far you are willing to go.
"Crapsjourney" stated what he would do sometimes was just call it a loss, STOP and just start over again. This is very viable when you look at the amount of individual shoe wins vs. losses.
My test data shoes overall wins (98.33%) averaged between 25-70 Units Profit. Doesn't take very long to get your loss back and continue on the Profit path!
To put an actual EXACT BR number on it, doesn't really work for me but, I think the test data shoes give us an idea of how many losing bet levels it takes before a Win occurs, getting us our money back with a profit. That is where the 160 Unit comes from and an amount that I would be willing to bet for an average 30% ROI.
Personally too, after I lose a 60+ Unit bet, sometimes I am looking to switch to Player bets or suspend betting to seek another table/shoe, and then pick back up where I left off at. Guess I am just not to hip to losing, when I KNOW I can be winning at likely 98.33% of the other tables...
Hope this helps and make sure to look at my example shoe I posted...hopefully, it will give you a better feel for things.