Hi lancel00t,
It's not you are displeasing, but without your source, we are not really able to help you...
So, I see strange things in your source. First of all, you are not telling which font you are using in purchase.c :
sfString oneStr;
sfString twoStr;
sfString threeStr;
sfString fourStr;
...
oneStr.SetText("1");
oneStr.SetTop(10.f);
oneStr.SetLeft(50.f);
oneStr.SetColor(sfColor(0,0,0));
This seems to be an error I think.
The rest is just algorithming questions, so not very important...