I don't know how much I've spent on cycling clothing and I don't even buy the good stuff I go for the performance/nashbar house brand stuff on sale. I also use a healthy mix of stuff from Target and Walmart in the winter when I am layered up and I find it does the trick. I also have purchased bike shorts from Modells for 20 bucks a pair and they are doing fine. My nicest item is definitely my long sleeve wool jersey though and even that tapped out at only 40 bucks.
Interesting enough I buy cycling clothing more than regular clothing, I also take care of my bike stuff better. And as far as cycling socks all I have are smartwool socks (from Sierra Trading Post)and cheap coolmax socks from Target and I use them on and off the bike