How much do I pledge on my goals?
The available pledge amounts are $0, $5, $10, $30, $90, $270, $810, $2430, and $7290. Normally, you'll begin with a $0 or $5 pledge, and with each derailment, the pledge will increase up to the cap you have set.
Pledges increase and decrease along this sequence only, so you can't set up a goal with a pledge of $50. For custom charge amounts, check out GTBee or the charge endpoint of the Beeminder API. Both of them are Beeminder-developed tools that let you customize a sting for one-off commitments.
You can decrease your pledge with a 7-day wait. If you have the fanciest premium plan (Beemium) then you can also increase your pledge at any time, but we think mostly you should just ride the pledge schedule up to your Motivation Point.
We put a lot of thought (and math) into the pledge amounts. In short, you want to very quickly reach an amount that motivates you to take being on the right side of your bright red line seriously.