What to be warned about?

"You get what you pay for." is often quoted by people who bought Chinese ARFs at prices too good to be true.

Fairly decent 30cc gas ARFs usually don't sell for $180'something. The quote really should be, "you aren't going to get what you don't pay for." especially when it comes to an ARF that is marketed like that one. I just did a google on "Katana 30cc" to see if any of the reliably good mfg's offered one and discovered pages of hits that mostly went back to one website. They're offered by a bunch of different retail fronts that don't even offer their own website.

With most ARFs nowadays, even the best will have at least one major flaw that needs rework, rebuilding, or redesign. The cheaper the ARF the more experience you need at building, repairing, or designing model airplanes. The fact that you're asking the question you are suggests you're somewhat new at this. The cheaper the ARF the "older" you need to be at this to turn any "too good to be true price" into a model that lasts you more than a couple of trips to the field.

However, I hope you get a response soon from someone who has actual experience with whatever brand ARF your link points to. Or any of the dozen other "brands" that seem to offer the same model.