Mach 2 is about $6 to 8 for a box of 50
http://www.midwayusa.com/viewProduct/?productNumber=974425 That is some expensive Mach 2 ammo.....HMR is not even close to that much!
New it is probably around $450. Are you talking new or used? If used, how does it shoot? Factory trigger or aftermarket? Laminated stock or walnut?