I know what your thinking:
50% OFF for an almost new 6ft T5 fixture with bulbs - That's amazing! But I don't have a 100 gallon mixed reef tank (or a 160 gallon soft coral tank, or a large FO tank)

Just think of all the stuff you could get if you got yourself another big tank! And with so much saved on the lighting you totally could get a new used tank off craiglist! And all the future money you will save by not paying 40% more on electricity for a Metal Halide - it practically pays for your itself! Think about it... ;)