Ive never shot the Darton Maverick extreme, but it should be a good bow. Its kind of short on brace height, but its a decent axle to axle length should help make it a forgiving bow.
Plus the CPS cam or extreme cam, is a great cam design, its the original cam and a half/hybrid cam. You cant go wrong with a hybrid cam, because one cable slaves them together, while the other cable does the work that two used to do. Matching cam shapes on top and bottom coupled with different cable lobes, allows for level nocking travel as well as a bow that cant go out of "sync".
Also, as was mentioned, 50 pounds is enough for deer anywhere. But I wouldnt use mechanical broadheads with that weight. Cut on Contact or even chisel tip BH's is the way to go with anything under 60# with an avg draw length and medium weight arrows.
My recommendation before purchasing any bow of course, would be to shoot it first. You have to get a bow that feels good to you.
Best of luck!

---Matt
FORGOT TO ADD:
If its a new bow for $300 its a good deal, the 2005 models go for a little over $500.
Also, as far as arrows and broadheads go. I would look at Beman ICS camo hunters...they are a good tough carbon arrow. For broadheads, you cant go wrong with NAP thunderheads or Magnus Stingers.
(I need to know more info to recommend arrow spine size and broadhead grain weight.)