i don't think price is the "be all and end all" of a setup like that, more about the right person wanting t i think. dropping the price will bring people that aren't thinking about a setup like that into the game i think but if you do sell all parts separately then i think that you'll have more luck as there may be some that are looking for just some parts although they may also tend to ask if you'll part with a specific piece separately.
as a complete setup it is a lot of money, as parts it's more achievable for someone on a budget or if they have specific skills that can save them money. If i was into another tank I would buy the tank and sump only and build the stand myself for example. what do you think?