I bought one of these too. I knew it wouldnt be anywhere near 250mw. However, mine is only about 50mw max.
I have tried contacting them MANY times about this and they will not respond in any way. So, good luck with your warranty.
If it had been 100mw+, the price would be fair, as it is actually quite well made, but considering the measly ~50mw, Im kind of ticked, as I could have easily bought a decent 50mw for $15
As for the label being wrong, it actually is not. It says <250mw , that means LESS THAN 250mw, and that could mean anywhere from 0-250.
The IR diode was measured at ~1W. It has all glass AR coated optics, (beam expander and collimator). The low power doesnt appear to be an alignment issue. It does appear to be a rather inefficient crystal set however. I know even with a much more efficient crystal set, 250mw would still be pushing it, but it should be at least in the 140-150mw range.