pipe screens could work, if you stack enough of them, but be sure to burn them first just 'till they glow red, not white, and you need to make sure the flame doesn't go around. some vapes use this instead of foam ceramic or mineral disks.
you want to save money, or just experience it before spending?
when i started i didn't have money or interest really but tried the lightbulb vape, didn't like it, made one, it was cheap, but took a lot of fiddling to set up the hits and again didn't like it, so the Hakko soldering iron works just like a silver surfer, and only cost me $39. plus a couple parts from home depot. check out the homemade vapes thread for other ideas and how they worked out for people.
but without wanting to sound like your dad, you should stop smoking pot, it's not good for you...always use a vape.