That is a reasonable price for that device and could be tempting if you just need it occasionally.
I also highly recommend buying it from an inland source, as usually a direct import from China is not that much cheaper after Postage fees, VAT, Customs, Currency Exchange rates and you normally get no warranty at all.
That depends on your seller of course....but I guess it would be at least 30USD for postage in case of a defect and then maybe you'll also need to pay for the return to you and end up with nearly the price of a new one....
I may keep an eye on that distance meter. Could be interesting to compare it to a "premium model". If it just works and is in specs it would be a nice grab for your toolkit at home.