This is probably the worst time to try and sell a Marauder. It won't matter much what features your MM has, or, your actual MPG. Americans are reeling from gas pump prices, and relief is not in sight. Knee jerk reactions will cause your MM to be percieved as a "gas guzzler" due to it's size and muscle car appearance, which is likewise true for the SUV market. 4-bangers are already pulling top dollar prices, and what you get for the MM probably won't help you much in the long run.
I'm not being sentimental about this. Hate to see you go, but try to make it another six months? You could do better, or worse then, but I don't think anyone can predict that far down the road. However, IMHO, if you are pinched for cash flow, selling your MM isn't going to give you any relief, other than taking a car payment off the table. If so, can taking a second job help?
Nonetheless, best wishes.