Wanting to sell it but have no idea how to accurately price it. I know what I paid for it new but tractor resale values are a foreign language to me. Any suggestions?
Do a search in google for "M6800 for sale" - don't put in the "DT" as many DT's aren't listed as such. That will give you a feel for what dealers are selling them for. Just remember that you are limited by your market area and the fact that you are an owner selling your equipment - cash sale and little if any recourse on the purchase. Don't expect to get more than a comparable tractor being sold by a dealer. However, your tractor does not have the DPF/Tier4 emissions. That is a big selling point ... push it. Also figure out how to widen your market area for advertising. Listings in CL in various markets is one way to expand the market area and make sure you have plenty of photos in your listing. Prospective buyers want to SEE what they may have to travel (potentially) hundreds of miles to buy.
I just bought an MX5100 with 190hrs from a dealer in PA and am shipping it 4500 miles to the middle of the Pacific Ocean. Even after the shipping cost, it will save me close to $10K over a new MX5200 from the local dealer.
I would check prices on Tractor House. That will give you a guide for asking prices. If you have a good relationship with your dealer you could ask them what the market is for your tractor also. Condition, hours, and location are all important. Around here Kubota sells very good. You should have no problem moving your unit.
I'm sure showing us pictures with the equipped option list would help get you in a direction. Also location as it seems region plays a large part of pricing.