I use far less weed vaporizing than I did when I primarily smoked. I get a full session from one load in my Arizer Solo, which holds around 1/2 to 2/3 the amount of bud as the bowl I used before. As for the high, I personally love the clean high from vaping and now when I smoke I feel more weighed down and the risk of a headache is a lot higher. Plus my lungs let me know about it the next day. I'm fitness conscious and work out a lot, so going back to inhaling smoke all the time is something I'll never do.
As for cheap vapes, I'd recommend spending a lot of time reading reviews here and on the vape sites. I think the Solo is the best bang for the buck vaporizer out there, and you can find them on eBay in the $125 range. Be sure to research the seller though, as most of them are not authorized dealers so you can't go back to Arizer if you have problems. If you catch a good sale somewhere like Vapornation, you can pick up a fully warrantied version around $175.