definately buy individually. my "toolkit" is as follows -

nashbar crank extractor/ 14/15mm crank arm fixing bolt wrench - $7 (awesome tool)
nashbar splined bb tool - $5
hozan lockring wrench - $23
wheels manufacturing 1/8" chainwhip - $18
aluminum pipe for knocking out headset cups - $0
aluminum pipe for setting crown races - $0
homemade headset press (bolt, nut, washers, couplings) - $5
allen wrenches 1.5mm-10mm - $5
chain tool - $10
2 cone wrenches - $12
headset spanner wrench $4
pin spanner - $6
15mm combination wrench - $2
tire levers - $3
park chainring bolt tool - $5
park spoke wrench - $7

and i have one of those durabilt basic home tool kits.

don't get me wrong, i would love a full park tool setup. however, it's hard for me to justify spending the money when the tools i have do everything that i need to do, and suprisingly well. i keep telling myself that if a tool breaks, i'll replace it with a higer end model. i ponied up the extra money for the hozan lockring wrench, because in my experience cheap lockring spanners are a complete pain in the ass. i'll get the pliers someday. i'd also like a nice workstand and wheel truing stand, but either one will cost more than my entire kit. if you occasionally build bikes, and perform basic maintenence like i do, then the nashbar, wheelsmith, and diy options are more than adequate