Wow..that bites. For our LYS the money for class goes directly to the teacher..we pay her. They expect you to buy your yarn at the LYS of course, but I don't know if they check. I know most do. I usually only have to pay about $60-$100 for a class. Never heard of one as much as you paid, but I suppose it's possible. I'll have to check.
Normally there is a pre-arranged number of students and if they have an extra one or two they ask the teacher. I think they also tell those signing up ahead of time what will be expected of them. We all kind of help each other, too.
As for being un-social, GG..I am shy, don't like being the center of attention, don't really like parties, etc. It took me a long time to get brave enough to even walk into an LYS. I'm very comfortable in there now. I've helped new knitters often and am very involved now. There's always a few annoying people in any group, but it's usually easy to avoid them. It's funny..we all sit in the same seats almost every week like an assigned seat.
Re: socks.. I don't knit two at a time, but I do cast on both socks at the same time or close to it. That way you knit a bit on one or the other. If you need to take your knitting with you somewhere you can choose the one that suits you.. like not taking the one with gusset increases or counting where it might be hard to concentrate.
For turkish cast on I was taught with these last socks (I have 6 cast on in various stages) we wrap 8, knit across the first needle, then using the tail and the working yarn knit around both needles. Then start your increases knitting the double stitches as one each time. Easy once you get the hang of it.