I found this pretty cool Inflation Calculator to look up the price of old guns and such in todays dollars. Fun to play around with.

https://www.officialdata.org/

M1 Carbine
1942 = $45
2018 = $695

M1 Garand
1942 = $85
2018 = $1,312

Thompson submachine gun
1942 = $225
2018 = $3,473