Can I get "Great" used speakers for $1800??

Sunnyjim, if you have the room, and the amps, you can't go wrong with Apogee Acoustics speakers. There are a number of models available in your price range, and most of them are mint. You can check out the models and their reviews at this site:

http://www.apogeespeakers.totalserve.co.uk/

How about NEW Revel M20 for $1500?

There's a lot of excellent speakers out there at that price range, many of which would go with your listening taste. Might be good to let us know which amp you are using, though. Some examples:
Thiel 3.6, B&W 802 matrix,Tylo Ref Monitors, NHT 3.3, Aerial (6 or 7?), Revel Performa 30, Infinity Prelude PFR.

Consider the following only if you have a high power/high current solid state amp: Magnepan 3.3 or 3.5, Dunlavy 4.
Best of luck.

B&W Nautilus 805, JM Reynaud Trente, Merlim TSM-Milennium.

All of these are bookshelf speakers, but I've had all in my home (Trentes right now). EXCELLENT sound.
All of these are Musical, Accurate, with incredible soundstaging and imaging, and tight bass down to 40hz or so.

I use a Rogue Tempest in triode (30watts) and get great strong bass from my trentes, let me turn it up so you can hear.

I'll second Thiels and Maggies.