almost any electronic ballast will run almost any fluorescent light, as long as the wattages are 'close'
keywords with that statement are electronic and almost
the $18 ballast you found might be magnetic, which might not be bad, but it's not as "sure fire" going to work as a similar ballast that is electronic
electronic ballasts also allow you to cheat and 'overdrive' a bulb, for example, you get a ballast that can do 2x59 watt bulbs (8 footers I think?) ... that equals a 118 watts, perfect for running a 96 watt pc
... you just short the two supply leads together
or you get a GE 432i that can run 4x32 watt bulbs, great for running a pair of 55 watt pc
's, you just short the red wires together for one bulb and the blue wires together for the other
cheating ONLY works for electronic ballasts ... do this with a magnetic and you'll just blow a circuit or start a fire.
here's a descrip of the cheat I'm using;
custom diy'd hood with 4x 24" t8's (17 watts each) ... they are wired in series, two each ... so it looks like a pair of 48" t8's ... I then have those hooked to a ge 432I, using two supplies for each pair ... so each bulb is being overdriven by about 2x ... and boy does it make a difference, but they run so hot you can't touch them ... so I added a small fan to draw air through the hood (but not to blow on the bulbs, since this cools them too much and you get dark patchs), now they are warm to the touch (about 115°F), which is an ideal temp
the bulbs are already past their prime (pushing 9 months), so I figured better to burn out then fade away!