Hi Gavriel, the short answer is: no it is not possible to change the range, but this is the second question (request for) about this feature just this weekend. So I'm thinking it might be something someone (maybe you) should put in the Ideas forum so we can all vote on it (you've got my vote)
You might have some success with a custom-made binning calculation like:
IF 0 <= SUM([Sales]) AND SUM([Sales]) < 5000 THEN '1 - 5 K'
ELSEIF 5000 <= SUM([Sales]) AND SUM([Sales]) < 15000 THEN '5 - 15 K'
ELSEIF 15000 <= SUM([Sales]) AND SUM([Sales]) < 50000 THEN '15 - 50 K'
It works, but is not ideal and may cause some issues.