3D printing outfits--how to submit a design to a company for printing?

Here is a link that lists several places to order 3D prints from:

https://all3dp.com/best-online-3d-printing-service

I have a printer and been printing parts and such.  For hidden parts it isn't a problem but for anything you want to be show and be smooth it takes a lot of work after (I'm using PLA).  The surface is not smooth.  ABS is supposed to be better (you can use acetone to smooth it) but I haven't tried to print with it yet.

If you do decide to buy prints it probably will not take much time until you can purchase a printer.  Mine was like $350 and I had to assemble it (part of the fun).  I can print about 200mmx250mmx200mm tall with a resolution of .1mm.  

Shapeways site does have a for hire section, found in the communuity pulldown tab.

Out of curiousity, I did a search for camping gear in 1/24 scale.  There is a few things, like a single metal bucket for $24.17 CAD.  I wonder how long that took to design, or is mostly cost in the printer/material?  Looks to be an expensive avenue to take in order to find unique items...

regards,

Jack