The Home Depot chin up bar works very well, in my opinion. Have had one in for a couple of months now. Mostly do dead hangs, but have done a fair amount of kipping. Thinking of putting a couple of 2x6s between a couple of the ceiling joists just to solidify it a little more, but that may be overkill and the engineer in me coming out. lol. About $30 in pipe.
A couple of plyo boxes made out of 5/8" or better plywood. About $20-$25 or so, depending on which plywood you get.
A set of PVC paralletes for < $10.
I bought a 12# medicine ball for around $30 before I saw the home made version here. Could make one out of a basketball and sand (not sure of weight - 20#?), I'm guessing for around $20.
Have some dumbbells, but no OLY bar and such yet, so don't have any numbers for you there, and those get a little more expensive, unless you get lucky on craigslist or something.