I picked up a used meggerinsulation tester on ebay, recalibrated by the firm that regularly sells them after they are deemed outof date. It has worked fine on the few occasions I have used it, and was a lot cheaper.
Out of curiosity, I ordered a Chinese one a few years ago. I does 50v, 250v, 500v, and 1000v, plus voltage measurement, with a digital display. Carrying out calibration checks, it proved to be well in acceptable specs.