Hellobee Boards

If you buy on sale from places like TJ maxx, or kohls you can get all those brands you mentioned like osh kosh, carters, etc for less..
For winter we bought hoodies, hats, cardigans and a pea coat

I would get jeans, Ts (long and short sleeve), pull over sweaters, and sleepers. I think you could get a good amount for $100 but probably not everything since you'll likely want to get him a winter coat of some sort.

I would skip the winter coat and do something like a zippered fleece. It's safe to use in the car seat and they can move around in them. I have several for my son from Carters and Osh Kosh, purchased for no more than $15.

I also don't like hoodies, because I couldn't get comfortable if he fell asleep in it and I had to put him in his crib. Instead, my son wore lots of onesies, pants and cardigan jackets by Baby Gap, and they were often reversible....they might come back in stock in the fall.

I also did overalls with onesie turtlenecks and that's pretty much it. He had jeans and cords, but hardly wore those, they were just not comfortable for him when he took naps.

eta: I wanted stuff with a knit waistband, nothing with snaps and buttons and all that jazz. Too much work! I also used onesies until he was busting out of the 24 month ones because i hate the bare back/diaper hanging out.