Mountain Bike or 4X4?!?

[bubs]

All my life i have been fascinated by bikes. I have been DH/FR mountain biking for about 5 yrs now. Its time to drive, and i'm thinking of taking up a new hobby. I also love automotive and trucks. I would love to get into 4x4'in with my friends,and have no one to bike with anymore. I only have the money for 1 of them. I either sell my bike and buy a truck, or continue biking?? Need opinions on this please