How to remove stretch marks on a low-income budget?

I see ointments out there to get rid of stretch marks, but they're always so damn expensive, and you always see this little bitty stretch marks. What about for those large, dark-purple ones that look like marker lines? When I was pregnant with my daughter, I was friggin huge and got lazy, so I sat on my butt all the time and gained weight everywhere. Now, from the backs of my knees and halfway up my thighs, I have those marker lines. :( I don't have lots of money to remove them, so is there a home-made product that can remove them? Or at least a cheaper product in a store that is guaranteed to help? Advice please!!! I would love to have these things gone!