Buying firearms is like furnishing your house. Make do with the Goodwill stuff while you buy one nice piece of furniture each year for as many years as it takes to furnish your house. Buy quality, it will last a lifetime.
Iconic handguns, to me:
Luger, Colt 1911, Mauser Broomhandle, S&W Model 29, the K-22, Colt 1873, Nagant and Webley revolvers.
Long guns : Martini-Henry, US Krag, Sprinfield 1903 and 1903A3, Garand, M1 carbine, M14, K98, Lee-Enfield No. 1 Mk. III, No. 4, and No. 5 Jungle carbine, Winchester 1873, Winchester 94, Ruger No. 1, and any quality reproduction of the Sharps or Rolling Blocks, and the new Stgw 44 in .22LR, it's going to be quite popular.