Great job mate, that looks awesome!
Decent kits are getting cheaper and cheaper by the day :p The Creality Ender 3 and the Geeetch A10 seem to be competing to see who can be the cheapest printer with the best features :) (both getting great reviews at only $200).
While filament & power costs are quite cheap, you would probably find it doesn't end up very cost effective after shipping large 3D printed boxes.
There are plenty of online services where you can upload an STL file and they will make it and send it to you, but it's usually quite expensive, and with the price of printers these days if you want more than 2 or 3 parts you might as well just buy your own printer.
A cheaper option might be for you to see if there is anyone in your local area with a 3D printer that is happy to print out commissions, however I have found a lot of people don't like doing this as it's time consuming, it can be hard to determine a fair price and they also usually have to eat the cost of any failed prints etc.