Alex rims are usually pretty good, those ones were used by Redline and GT at times, not the high end bikes from memory, but still better than box store!
Anything with a GT badge should be fine, so the wheels are probably pretty good in they are a matching pair.
The stem looks interesting, I am sure I have seen that before somewhere...
Pinch bolt cranks are usually pretty good even in the lower end, unsure on what type or brand they are exactly though, they may be mid to high, someone on here will know...
The sprocket looks like it is a cheaper stamped steel style, but looks can be deceiving...
The frame looks a bit like a DK I had a while back, but not sure, I am thinking the bike has been pieced together from different bikes and parts...
Guessing by the fact it is threadless forks and U brakes, it would be late '90's onwards, the forks themselves are unlike any I have seen before, but my experience is limited...
I would guess it is not a box store bike, more likely a low to mid bike store bike, but I am only guessing, someone on here will recognise that stem I am sure and that may give a lot more answers.
Luke.
Edit: Just did a search and the stem I was thinking of was an Odyssey stem, but it is different, similar, but different...