Are you stuck on an all-in-one tank, i.e. the nanocube? Honestly, nanocubes are very difficult tanks, becuase of their limited water volume and lack of a sump.
I would try to buy a used system from someone here on this board, or Reef central instead. There are some really nice 30-40 gallon tanks being sold for about 25% of their original price. (FYI, I would not expect to recoup any more than about 25% of your system costs when you sell your used tank...I recently sold my tank and wound up with significantly less than I hoped and this was with many top of the line parts....I still have many things for sale, but its hard to sell reef stuff at this time because the market is flooded).
So...on that point, with so many tanks available, I'd figure out the space you have available and try to get a really nice 30-40G tank, stand, lights, skimmer, pump, corals, fish, etc...all in one. I bet there are some really, really nice tanks, fully cycled with all the goodies for less than you would pay for the nanocube 150HQI alone. And, I would venture that these tanks will, in the long run, be better for your inhabitants and your reefing education too....
Best of Luck,
-Kyle