My advice: Don't buy a folder unless you can test ride and fold/unfold a few times. Any folder can look good or decent on paper, but it's real world function that counts. A few things to consider:
Does it fold/unfold easily, or is it a struggle?
Do the folding bits seem well manufactured, or are they cheap-feeling and probably won't last?
Once folded, does the bike stay folded with aids (straps, magnets, catches) or does it flop around in the folded state?
Can you wheel it when folded, or do you have to pick it up any carry it?
Does the chain stay inside the wheels when folded, or is it outside the wheels when folded? Important if you don't want grease staining clothing, car carpeting, etc.
Do the folding bits make noise when you're riding? Squeaks, rattles?
Is there too much play or a feeling of looseness to any major parts? Stems, handleposts, seatposts, etc.
Is it easily adjustable to your specific riding needs? Adjustable length stem, for ex.
Cheap folders are an exercise in frustration, because they often don't meet many of these criteria. Sometimes with folding bikes, you're not only paying for less total weight and better parts and frames, but better design and execution.