No trim for me, but I do separate the fat when I pull it. I also smoke it fat side down toward the heat in my WSM. I understand what folks say about the "basting" when you do it fat side up, but I like the all round bark better when I smoke it fat toward the heat.
I prefer bone in, but the best price around here anyplace I shop is at Costco, two boneless butts packed together usually $1.99 to $2:49/lb. I saw $3.99 today at the grocer for a pork butt, bone in. I'm buying less and less beef and pork from the grocer because their prices are ridiculous.