I sell Magpul copy products... and I've handled all 3 versions of magpul (copy, PTS and RS)
Copy magpul are actually really well made, and compared to PTS stuff, they look and feel pretty similar! (except for the UBR and PRS stocks)
Copy magpul's material is more like a textured ABS plastic, while PTS is lower grade nylon fiber, and RS is Dupont nylon fiber...
but for airsoft, and for half the price, why not?, if you're not picky about owning fake stuff, repro magpul items will be great for your tight budget!