set consistent position of 3 buttons inside 3 respective columns

[GetRig]

I am using one of the Envato Pro templates which includes a price table with 3 columns. At the bottom of each column is "sign up", however because the columns have a different number of words in each, the position of each of these buttons isn't horizontally in line. This looks quite messy. See attached for how it looks. How do I set the position of these buttons to be consistent across the columns? Is there a way to fix their position from the bottom of the column regardless of the content in each? Note that I have tried "absolute positioning", however while it looks ok in envato editor, it doesn't translate across to the live website. Thanks!