I have never used a cintiq myself. But I do have a display tablet by xppen. I will say, I much prefer the display tablet over anything else. I would be more worried that it is a scam considering how low they are offering it for and how pricey cintiqs can be. But! If it is a scam, I will say that you can also save money on a display tablet by going with xppen over cintiq. they are an amazing brand and just as good, sometimes I think better, than cintiqs. also, most older cintiqs doesn't have express keys, which I live off of. But most xppen do.
So as for if a display tablet it worth it, absolutely, but I don't think the price of a new cintiq is worth it when there are other good ones for better price for the same thing. So if you don't go with this one but want to buy one in the future, maybe do some research on xppen!