Someone came by looking for “how much does a tommy gun cost?” Before I answer that, I will need to provide some background.
The original Thompson Sub Machine gun is a fully automatic weapon. It will fire as long as you hold the trigger down.
The modern Auto Ordinance Company makes a semi-automatic one-shot-per-trigger-pull look alike
The few ads for an original “Chicago Typewriter,” a full auto version of the Thompson, I have seen for sale for at least the last ten years have been in the $15,000 and up range. Mostly up for a mint or near mint specimen.
On the other hand Kahr Arms/Auto Ordinance will sell you a semi-automatic look alike that will fire once for each pull of the trigger for between $1,300 and $3,000. The Auto Ordinance catalog is at the link, and you can click on the pictures for the details.