So nice to have you here with us! Thanks for joining Knitting Help!
I think it's perfectly OK to knit with the best yarn that you can afford! Certainly there are many many fine yarns that are affordably priced! Joann's has quite a number of yarns that you view before buying!
If you don't mind purchasing yarn 'online'...the two websites that immediately come to mind are:
Knit Picks, and Elann!
Both sites carry many fine yarns that are affordably priced! A low price doesn't mean low quality!
First of all, before making a decision about the yarn for a particular project, decide whether or not you are willing and able to handwash the item! If not, then shop for a yarn that declares itself to be machine washable! Superwash wools are just one type of washable yarn. And of course, almost all acrylics are washable!
Next, shop for the 'character' you'd like in a yarn. For instance, I love tweeds. So I will always browse the tweed offerings of any yarn website!
Wherever we go, we can ALWAYS find a snob, right?
Shoe snobs, handbag snobs, coffee snobs, wine snobs, car snobs, and of course, yarn snobs!
Take heart! There are more of US than there are of THEM!
It's more important to try to knit well and have fun doing it!
It sounds like you are off to a good start, taking classes and such! Good for you!
You're interested in mastering your skills! Knit with any yarn that pleases you!