These look an awful lot like the Pakistani harps which do NOT have a good reputation.You should buy from a reputable builder. Personally, I would never buy an instrument without looking at/hearing it first...
One basic thing to check is whether the tuning pins are uniform so you can reliably tune it. Also look at the neck from the front to see whether it is warping to the side.The direction of the wood grain is also important- the neck will snap if the grain goes the wrong way.

Where do you live? Perhaps there is a dealer/ builder near you
Have a look at www.harpmall.com

These are good entry level instruments at a reasonable price
http://traditionalharps.com/TastyHarpsMenu.html
Or http://www.stoneyend.com

All the best- Julia