Also apologies if I passed off as rude in any way earlier, the question was directed towards playbox who seemed to be taking words off of ya. I wouldn't assume there's no value in a service or no reason to get a 3d print without a printer.
No, you're good.

You weren't wrong, just that it depends and at the time we had no idea what he wanted. There's a lot of variables in keyboards and 3d printing.
I wouldn't say there's no value in it but it is a catch 22.
To get the most out of it you need experience but if you have experience you probably don't need the service.
(although I modified it a tiny bit, but not in any major ways)
Famous last words...
It's easy to mess something up in digital that used to work fine, and "tiny bit" is relative. What may seem minor can lead to major problems, I can't tell you how many minor changes I've made led to massive redesigns or conflicts.
Make sure the on demand service is pricing with the infill and perimeters you need, when I did work for them they always without fail, under estimated the price (by a ton). Also layer height matters a lot, smaller layers feel better but crank up print times.
The difference? (based on a 5x6 Dactyl design on Thingiverse)
1 perimeter, 10% infill, 0.2mm layer height = 300g plastic and about 12 hours print time.
vs
3 perimeter, 40% infill, variable layer height or 0.12mm height = 350g of plastic and about 30 hours of print time.
12 hours print time (plus prep and cleanup), sure, I'd do it for $70 but for 30 hours, probably not and if you're on a low end home based printer that's probably going to be closer to 45 hours and that's quite a long print time for those machines.
3d printing is only cheap if you own the machine and even that's not a hard rule.
Worse still, most of these designs are by people with 3d printers meant for people with 3d printers and some are done by people with no 3d printing experience at all. And truth be told, even when they "work" they're often not great or as simple as they seem. Remember, it's a bunch of amateurs and they often work with whatever they have, a bunch of random parts and cheap digital calipers. No hate, just saying don't trust everything on these sites. I've seen designs where they used 5 different screws because they only had 2 of each size, designs by people who just imported some random cad file to be "helpful" and others were just so badly proportioned they would never work in reality which is why they designed it, posted it and never showed off a finished model, they never got it to work. I trust almost nothing I download that is size specific regardless of how many others printed it and run as many tests as I can prior setting the whole thing to print because I've been burned too many times.