Sorry to have to intervene, but discussions of commerce are always off topic, so let's leave it at that.
If you really were to start selling these the machine shop supervisor would probably get very interested in a negative way.
Engineering method of estimating price for a sustainable business: take your fixed costs and multiply by 5
material
hardware
machine shop time
Machine shop supplies and incidentals
hourly wage
If you put an honest figure on these you will probably come to something close to what Sputnik/Anvil/Bringhelli/Henry James are charging.