tominator, I haven't tried the $3 spray cans but from other cans that i have used for vaires things which were the same price i think the results would be less than satisfactory.
I have seen good results recieved by using the other other spray paint that they have. I think that its powerplus or something it comes in two can sizes 150,375ml. these retail for $7.95,$12.95. For striping the paint If it is an acrylic just use metho or windex. For an enamal you could see if you can get some coastic soda. I don't know were you can get this from, maybe a chemical supply place could point you in the right direction.
Cheer Trev