Stack the wood neatly in your trailer and figure the volume. Post pics with tape showing dimensions and sell accordingly based on cordage value in your area. Just my 2c.
Try as I might, I can only fit 3 Ricks in my small truck fully loaded. I hate that term "Rick" It just sounds like something the seller is going to pork you on before he pounds a tall can of Milwaukee's Best and a nipper of Fireball, tossing the empties along your driveway as he roars into the sunset. Here in the wonderful state of Connecticut you can only sell by the cord, not face cord, not truck load, certainly not by the rick. Cord, half cord, quarter cord etc. Of course like anywhere else you'd be hard pressed to stack what you paid for and it adding up.
And then there is this guy. At least he never says how much he has. Also note, most sellers take the picture from the back making it much harder to tell how long the bed is.
Place I worked for in the past built a 10' pickup bed for a customer on a Chevy 3500 dually...obviously had to lengthen the frame too...it was a weird lookin thing. I had a full cord stacked on my truck once...had sideboards on and it was stacked to the roof (8' bed F250) ole girl was a squattin a bit...had another cord or so on the trailer too!
Years back id take a full cord on my old green F150 to a delivery half hour from me. I used to put plywood sides up to the ladder racks. 40-45 mph down the interstate with flashers going.
Every year without fail I see this pic in a wood ad. I get it, its humor but... You know the seller isn't going to make it thrown in level with the bed rails.
I bet quite a few guys on here load a full cord in their trucks. I do. There was an ad several years ago for "as much wood as you can fit on your pickup truck" and he was asking something like $20. I asked him if I could stack it and he said he didn't care. I stacked a little over a cord on my truck and he told me not to come back. I didn't care. I figured one load for 20 bucks was worth it since I didn't have to cut it.