I was thinking, we older guys might list the firearms we bought before 1980. I'll start out, my first was purchased in 1971, two years after I got out of the Army.
1971: Marlin 336C 30-30 lever action rifle, Marlin/Glenfield Model 60 .22LR semiauto rifle (both bought new)
1975: 1913 DWM P08 Luger 9mm semiauto pistol (used of course)
1976: Colt Series '70 Government Model .45ACP, S&W Model 19 .357 Magnum revolver, Ruger Mark I Target .22LR semiauto pistol (all bought new)
1977: 1948 Argentine Ballester Molina .45ACP semiauto pistol (used)
1978: Remington Wingmaster Model 870 12 gauge shotgun (used)
1979: Star Model PD .45ACP semiauto pistol (new)
The biggest issue with assembling an AR isn't so much getting the parts together right - it's getting the right parts together. You'll remember the quality of a gun long after you forget how much you paid for it.
US Army 1966-69, VFW Life Member, Retired Geek