I have one of those meters and if I find it insane that they could be sold for $150!
The meter to me at the first sight looks very nice and interesting, but is actually quite annoying (at least for my use case).
First, the banana plugs. As already mentioned, they have connection indication and detection and that makes them difficult to use with regular banana jacks. I use unshielded banana cables with various type of small connectors at the other end to do measurements on small components. Those bananas have bulge in the middle. The spring at the bottom of the receptacle always keeps pushing them out, so connection is very poor.
Next, there's the backlight. I actually like it quite a lot, but it's programed to fade away very quickly, so it's usually only good for one measurement. That means that you must keep pressing the backlight button all the time!
Next, there's the bottom of the meeter itself. It's not flat, so the meter isn't stable when standing on the workbench. It can tip over quite easily.
There's also the auto shutdown, which is in my opinion very badly implemented. The meter, as far as I see, has a timer which measures for how long it's on. After some time passes, it will beep. Then after some more time passes, it will beep again. After few beeps, it will turn itself off. What I really hate is the fact that as far as I can see, meter operation DOES NOT reset the timer!!! You can have changing measurement values, operate the switch etc. None of that will reset the timer. That is probably the single most retarded thing on the meter. I have another Mastech meter, the MS8226T, and it automatically resets its own timer when the measured value is changing or when the switch is operated for example.
Then there's the switch layout, which I don't particularly like. The off position is in the middle, on the left are the volts and amperes, on the right ohms, diode/continuity, capacitance, hFE and frequency.
So if you want to switch from resistance measurement to voltage measurement, you need to reboot the meter, since it has to go through off position in order to go to the volts range. That takes a couple of seconds that could have been avoided. Then there's the position of hFE option. It uses mA and COM receptacles, so if you want to get to the frequency range, you must bear the flashing red lights and beeping alarm which happens if there's an incorrect connection.
While I'm at hFE, the adapter which needs to be used for that option to me looks unusable, or at least I haven't managed to get any sane reading from it (and yes, I did read the manual and no, its use isn't explained, at least in the version I got with the meter). On the plus side, I don't really need to use that option a lot.
In my opinion, I'd move the off position all the way to one side, and have the hFE position all the way on the other side of the switch. This way, we wouldn't need to reboot the meter when going from ohms to volts and we wouldn't need to suffer from unneeded warnings when moving to frequency range.
Finally, there are the probes themselves. What I really don't like is that only the very tip of the probe is exposed, the rest is covered in plastic. In some cases, this makes it difficult to connect the probes. For example, they can't be connected to binding posts, or make a connection with internal part of Schuko receptacle (not that I'd recommend using this meter on the mains).
On the plus side, I like the design of the meter and the internal PCB assembly looks much better than the older MS8226T I have. It almost looks good to me.
I won't write much about the readings, since the best meter I currently have is MS8226T (Flukes are incredibly expensive here!). The read values match, except for non-sinusoidal AC voltages, but that's to be expected since this meter isn't true RMS.
All in all, it seems to be a not too terrible meter and the price of around $30 looks about right to me. I'd say that the sale doesn't look like it's too good to be truth, it's just that the normal condition looks too bad to be true, making the sale look suspicious.