How much do I pledge on my goals?
The available pledge amounts are $0, $5, $10, $30, $90, $270, $810, and $2430.
Pledges increase and decrease along this sequence only, so you can't set up a goal with a pledge of $50. If you're interested in 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 shorter-term tasks.
(We put a lot of thought (and math) into the pledge amounts, if you're interested in the development...
The idea is that you want to very quickly reach an amount that motivates you to take your yellow brick road seriously. At first we thought we’d just double the amount each time. But with that rule, by the time you’ve reached the pledge amount that you don't want to lose, you’ve actually spent approximately that same amount in previously paid derailments. That's not so great, since that was the motivating amount you didn't want to lose. But you already have! So we have it increase more steeply. With the above schedule, you’ll never waste more than half of the amount that eventually motivates you to stay on track.)