im gonna guess on this price range but it will probly be a bit more:
+$1000.00 & here is why,
$200 for a good skimmer
$200 for a nice sump(unless you make one thats nice but probly same range)
+$500(unless you find it used. this includes stand)
and that is just some of the stuff you would need.
others would be heaters, salt, gravel(agrogate), LR, Lights(depending on what your doing could be in the $500 range just for lights)
i build my 55g and it have about $1200.00 and i found alot of stuff used. i did make my own stand. i built my own sump. but there is alot of cost. my cost is to this day including all my fish lights everything.
HTH
good luck
i would check CL for someone getting out of the hobby and get all there stuff. probly a much better deal if its all in good shape that is