Don't ever treat a cheap 5mW as 5mW. It's more likely to be significantly higher. The companies have a machine which spouts them and they then pick them up and (possibly) meter them, then plonk them into the relevant bucket. 5mW, 10mW, 20mW, 30mW and 50mW usually. But then more people want 5mW ones because they're legal in the US, so they stick a bunch of higher powers in. Well... that's how they operate in theory... tbh, they probably don't bother metering at all. Just have a machine that poops them out and then when someone orders one of any power from 5 to 50 they pull one out of the bucket and ship it.
randomlugia, maybe you should mention that in your guide... the way that if you order a cheap 5mW it's likely to be far higher than 5mW.