I was in Old Navy last weekend and saw some nice capri length leggings that were lighter weight. I like the spring weight because I always wear them as a layer, not as a stand alone item, so light weight is like super heavy weight tights. I also love capri length because it eliminates unnecessary bulk with my boots.
I know you mentioned quality, and they aren't quality,but they are a great way to pick up a pair and see how they work without being out a ton of cash. I have a hard time thinking of leggings as an investment item.
Hilarious full disclosure follows: My all time favorite leggings? Old Navy maternity leggings. They are cheap and they have a great waistband that lies very flat and doesn't create extra bulk. I bought them while pregnant and wore the heck out of them, then recently bought new ones. The rise is high enough to sit mid belly. However, I know the idea of wearing maternity wear outside pregnancy is taboo for most of us, so I don't expect anyone to do like I do. So just laugh and know that some kook (me) is out there wearing maternity leggings long after baby's born, and liking it.