Well to give you an idea, I spent $850 on a CA M15A4 Carbine and 13 star mags.
Thats not even including a charger or battery packs. Then again, I have a friend who said he'd build me some and save some money.
This was my research as to what weapon to buy as my first gun.
I Googled all the real firearms that the military uses, US Army, Marines, Canadian Forces, etc, you'll get a good idea as to which gun would be better suited for what type of application.