Do I need your PCBs?

Wait... what?

Well, ok... this might need a bit of explanation.
The SMuFF was mostly built upon standard off-the-shelf components for a reason. They're usually readily available and fairly cheap, compared to some DIY boards that are not being mass-produced.

For example, a 3D printer controller board that's widely available, such as the SKR E3 V3.0, costs round about 40 (insert your currency here). Equipped with everything a 3D printer needs, such as the stepper motor drivers, MOSFETs for heaters/fans etc. For a DIY board estimation, roughly double the price and there you have it.
That's because stuff produced in high quantities gets a better pricing for every item.

Same goes for the other equipment, such as the relay board.
Sure, there's a downside to this: You sometimes get (and pay) more than you've asked for. The SMuFF doesn't need heaters, still the board has got them.  You may need a different layout or a different pin-out, you may get a different form factor, but that's not what you'll get, unless you create your own design. You have to work with what you've got from the manufacturers - it's as simple as that.
So, if stuff doesn't fit or doesn't suite you, you'll have to make it work anyways.

That's what the SMuFF and it's satellite projects have in common, they all can be built using standard components. Some of them may need "only" a custom wiring, some of them need a solid set of skills in order to build them.

So, then why did you design them?

For various reasons but mostly because people with a lesser skill-set were constantly struggling when building those components and these custom PCBs are easier to handle and give it all a "Pro" look. It's really a matter of choice.

Eventually, it's up to you whether you want do go the DIY route or you'd rather go shopping.

The only PCBs I'd recommend buying are the one for the SFB (if you plan using one) which has been tested by a few makers and the SMuFF-Backbone, once it's being fully tested. The latter didn't happen yet because of the low demand and I've stopped shelling out my money for stuff that I've already DIYed.

The SMuFF Backbone was my latest (and most likely last) addition and it's made to incorporate all of the single components into one PCB, such as Buck converter, Relays, Multiservo and connectors. All of them clearly labelled, so wiring becomes a breeze.

When ordered as a fully or partially assembled PCB, it'll save time but not costs.
I.e. if you order 1 single PCB, it'll be around 70-80 €/$. Those prices of course will vary, depending on the current supply and demand situation of electronic components on the market.
Getting the PCBs in higher quantities will make them significantly cheaper, though, you might ask yourself "Do I really need 50 of them?"...