I can tell you I got this Atlas (Marcato) machine from Amazon for USD71 shipped. I like it. Runs smooth. Has appropriate settings. Etc. Can't complain about anything.
Amazon.com: Marcato Atlas Wellness 150 Pasta Maker, Stainless Steel: Kitchen & Dining
I tend to trust Amazon user reviews, if there are more than a few reviewers. Going by that, Atlas, Cocina Pro, and Imperia get good reviews and are all about the same price. There seems to be nothing much less until you get down to under USD30, and that one has problems.
I took a quick look, and Atlas machines are all over eBay, used, for well under USD50. I think a pasta machine is a good prospect for used purchase. So many are given as gifts or bought on a whim by people who end up only making pasta once, that if one is described in excellent condition and still has the box and maybe the manual, it's a good bet.
There are indeed some poor examples around. Roma seems to get some poor reviews for cheap construction.