Funny. In 2007 I bought a used Black & Decker 18V set from a pawn shop for $100. It has a small circular saw (5" or so?), a cool drill/driver where the chuck part comes off and reveals a hex socket underneath, so you can keep a driver and a drill bit on the same tool and switch between them just by pulling off the chuck part; a reciprocating saw; and 2 batteries. Those original batteries are long since worthless, but the tools are still going strong (I found some drill/drivers at Walmart on clearance for $35 each a few years ago that use the same batteries). I now have a corded circular saw, a table saw, and a compound miter saw, so the little circular saw doesn't see much use; and I haven't really needed the reciprocating saw since I demo'd the wall in my condo; but the drill/driver is still my main piece. Yes, it's heavy and bulky with the old NiCd batteries. But it's got a nice gearbox and easy torque settings.
Of course, I'm just a simple homeowner. I don't rely on these tools to make a living. But those tools have seen me through 8 years of minor household projects. Yes, they are orange-and-black junk from China/Walmart, but they have been sufficient for my needs, and they have never let me down aside from battery issues (even so, a fully-charged battery will still last a full day of moderate use in the drill/driver). I wouldn't hesitate to buy a similar $100 used set from a pawnshop again, given the ability to test each piece for functionality.