They’re pretty rare and pricey here in the States. One possible solution is this OKI model—you can check out the offer here.
It features networking and duplex printing, uses 4 toner cartridges, and has a max duty cycle of 75,000 pages per month. Generally, it doesn't make sense unless you're printing at least 1,500 pages a month; if you're looking at a steady volume of around 5,000 pages monthly, this thing will last a long time under those conditions. But honestly, it's a beast. You won't have any trouble running it close to its max duty cycle; it can handle it.
The toners yield about 7,500 pages, you swap the drums at 30,000, the belt at 80,000, and the fuser at 100,000 pages. Of course, the actual page count per toner varies depending on how much ink you're putting on each page, and those other parts (especially the drums) tend to last even longer if you aren't feeding it plywood or sheet metal 😬. Basically, OKI builds stuff tough. They've been in the game a long time (alongside Kyocera) and they know how to make a solid printer. My personal favorite would be Xerox, but that's way too expensive...
You can get a rough idea of the pricing here all in one spot.
You can learn more about it here:
http://www.printerland.co.uk/OKI-C822dn-P122996.aspxhttp://www.trustedreviews.com/OKI-C8...Printer-review
However, since I don't know how much you know about this topic or what you actually need the printer for, I have to point this out:
Almost certainly, no printer is going to give you great results or color accuracy right out of the box. Color reproduction is a system involving everything in the chain: the scanner, the monitor, and the printer. You have to sync them all up. This synchronization happens through a process called calibration based on the specific standards required for your work. There are software solutions with calibration templates (printing complex patterns, scanning them, measuring them on the monitor, then printing and re-scanning) as well as hardware tools (calibrators), which aren't cheap. You can only expect professional results after a professional calibration is performed. Not to mention, you'll need a decent scanner and a good monitor (usually an IPS panel) to ensure the colors stay true.
A user can handle calibration themselves using software that comes with some equipment (usually a scanner), but you can also hire a pro to do it if you want truly perfect results.
Check out more info on calibration here, and a solid US company specializing in this field is definitely HSM, whom you can contact for professional equipment calibration services. They also offer high-quality scanning solutions.