Unfortunately, a standard internet MO is being applied here. Like many internet discussions asking for advice about product A, the asker doesn't receive much, if any, feedback directly about product A, but folks are quick to tell the asker they really need to spend more money for products X, Y, or Z.
In the case of Hi-Point, if one actually reads threads about the guns, including this one, you'll find most of the negatives are from folks that have no personal experience with a Hi-Point product. Always a "I heard..." or "I've read..." critique. Sometimes, not even that much supports of their opinion. If you actually talk to a Hi-Point owner, you'll find the guns are inexpensive and go bang when you pull the trigger. What else does it need to do? Yes, if you have the budget, there are weapons with more features or that simply look sexier. Some, like say an XDm will function in more extreme conditions than a Hi-Point, but how many personal civilian self-defense weapons will be buried in the sand/mud/ice and then expected to fire immediately?
All mfgs will make a bad example of even a good design so one-off anecdotes need to be looked at with a bit of skepticism.
I had no trouble doing my CCW qualifying with a Hi-Point C9. Groups were as good/better than the guys carrying XDs and I certainly had less trouble reloading than they did (are all double stacks that hard?). Worst thing I can say about the C9 is it had some FTE/stovepipe issues on the first shot when the magazines were new if loaded to capacity. Something I've read is not uncommon with many brands and my LC9 did the same thing. Simple resolution is to load one shy of max for a while until the springs lossen up. Granted, I eventually want to get something with more features...higher capacity being one of those features, but my family is protected by a Hi-Point C9 without reservation. Better to have a Hi-Point today than run into a bad guy while you're still saving up for something better b/c of some experts on an internet forum, eh?
To the OP, if you're still reading. $150 used is actually probably a bit high IMO, but given the current "gun control" media hype, not unexpected. MSRP is under $200. My NIB C9 was $160ish a few years ago. I personally wouldn't try to actually concealed carry a Hi-Point, they're a bit of a brick, but some folks seem to carry 1911 frames without issues so YMMV.
I would also check the ergonomics of any weapon you consider. I agree with some in this thread that the Ruger P95 is a good example of what one can get for about 2x the cost of a Hi-Point. ;-). However, I don't like the location or operation of the safety/decocker on the P95. Thumb up to fire just seems wrong, especially when the reach is all the way up to the slide. At the P95's price point, I like the Taurus 809 for its frame mounted safety/decocker and its thumb down to fire, just like my C9 and LC9.
-Brent