Change sell/buy value on some vehicles, fix bug.

M4A1 now costs 150 and sells for 75
M4A1 CCO now costs 150 and sells for 75
M249 now costs 250 and sells for 125
Mk48 now costs 300 and sells for 150
M240 now costs 300 and sells for 150
Lite / Premium money script fixed, was string instead of int.