You don't need boots; most people already have comfortable running-type shoes that will do fine, unless they have slick soles that won't hold in mud or on wet rock.

Fleece is another thing that's undoubtedly already in most peoples' closets; if not there is plenty of it at big box stores at a fraction of what you pay at REI and similar places, and just as good quality in most cases. At thrift stores, I'd hold it up to the light to be sure there are no thin spots.

And watch for sales! Costco, at least in the Pacific Northwest, right now has merino wool socks that most local hikers consider identical to Smartwool, something like four pair for $12. I don't have a membership, but my daughter-in-law does--I'm going up to visit tomorrow!

Another current Costco item--boys' down jackets, $30; supposedly the XL size is equivalent to a men's M.

These items may be a few ounces heavier than the expensive kind, but not so much heavier as to cause an undue burden--and they're certainly easier on the wallet!