I read that the current Colt branded knives are pretty well made. I have not paid much attention to the pricing, but I believe that they are inexpensive.
The Colt branded slip joints are well made, I don't know about their one handed folders. Their slip joints are currently being made by the same people who do the rough rider knives to my knowledge but they have slightly tighter tolerances for QC to my knowledge being one of the main differences as well as going for some of the more modern materials such as titanium nitride coating.
I own 2 of their slip joints and they are built like tanks though the blades are 1/8in thick which is too thick for my preference so I haven't put them through much use, and these are the newer carbon steel blades they put out but I've heard good things from the one person who did put it through it's paces. I own 2 of the rough riders as well and they are also quality knives for the money and the 440a works pretty good for what it is. Rough Riders your looking at $5-10, Colt's your looking at closer to $10-15 and they are both well worth the money.