two ways to look at this.
1.) You're ONLY losing a grand after owning a truck for 4 months. That's really not bad in the grand scheme.
BUT
2.) At that number you've lost $250 per month you've owned the truck.
Looking at it by the numbers, you lose a grand on your truck plus the 3300 in finance charges or $4300. Amortized over 72 months, that's only about 60 bucks a month. The 8 speed will save you a little fuel, but not a lot really, and it will probably be offset by the heavier crew cab. But, if the added utility of the crew cab means you can carry people more comfortably than before, and you do it on a regular basis, I say go for it.
I love my crew/8spd. The only thing I'd do differently is get the 6'4" bed instead of the 5'7" (the shorter is fine for my purposes, but it is a limiting factor for future home projects haha), and I'd get the 3.92 gears instead of the 3.21s.