Well i have a good job, Not SUPER NUTS money but enough where i can actually save a good bit and really do this, Been saving for months i have $8,000 saved at the moment BUT with the M16 the sky is actually the limit with customization. The possibility of buying a HK416 upper and making it functionally a Civilian owned 416 (my dreams come true) or like you said almost ANY other Caliber and the only part i can't replace is the part that literally is under 0 pressure and no Real risk of breaking so...looks like i'll have to grit my teeth and keep saving until l get to the number i need. Thanks for the advice