Just buy a cheap set torches used and a 4-1/2" grinder. You should be able to cut your own bevel if you plan on making a go at it in the field. Beveling machines are great, but it is sort of like anything else you should be able to do it manually before relying on machines to do it for you otherwise they will end up always being a handicap. Usually if you watch around jobs sites the scrap gets dumped a lot. I don't know how many feet of pipe has been tossed to the side after jobs never to be looked at again.  The paper and Craigslist (http://www.craigslist.com) is a good place to toss up a want ad and see if a contractor is looking to unload some excess stock. It is not unheard of for companies to they sell off their overhead in leftovers from old jobs once and awhile, Cianbro recently did it up north. Thing with buying coupons is you will have one or two beveled sides then you will weld onto the factory bevel then what toss them? of course not what a waste of material! You will cut away the weld put a new bevel on the pipe and weld until there isn't enough parent metal left to do that with. Usually buying coupons is done when there is testing involved and the coupons have to meet a certain spec. A lot of places you buy coupons from are throwing a Wachs machine (http://www.wachsco.com), lathe or whatever on there to bevel it, not always a torch cut bevel. The machining results in a better and more consistent testing piece but with a higher cost incurred. Good luck on the search!