Here is why I am wondering about it:

I am developing a huge patch, it is a very complex sequencer. It works really well and offers things sequencers normally cannot do. I use it in my bands myself. It is starting to be "complete." So I am thinking about offering it to the outside world. Six years of work with a very functional result, usable even by people not familiar with Pd. It feels like it should be worth something.
How would you approach this?

Thank you for your thoughts!

This forum is a place where fundamentally the community help each other for free.
Sometimes users offer money for help, especially for a complex project, but usually get no response..

So it is unlikely that you will get anyone to pay for your patch by advertising it here.

I am no expert on the licensing implications of charging for the use of your project, and I don't think you will be able to protect any patch that you sell....!
I think you will have to study the licenses yourself, but someone might reply to this thread as there are some very knowledgeable developers that keep a keen eye on things.

So I would guess that asking (on this forum) for payment would not be seen favourably, but if you wish to advertise elsewhere then you need to check the software licences for Pd and for all the external objects that you will include in your patch.

David.

I don't think you will be able to protect any patch that you sell....!

Maybe it's possible with compilation, PlugData is able to do this : https://plugdata.org/docs/book/CompilingPatches.html

You would of course need to make sure that you are not including any code/abstractions from someone else, unless that code has a license that allows you to distribute/change/sell/etc.

My bandmate is pushing me to sell it

On occasion, someone has seen something I've made for myself or for a work-for-hire job (e.g. a bike chain sleeve, a tube circuit, or an escape room feature) and has encouraged me to create a business selling it. I"ve offered these folks 50% of the company if they'd just help me set it up and navigate all the business stuff. So far, no takers, which to me is very revealing.

My bandmate is pushing me to sell it, and I am trying to explain to him that it does not work like that in this community.

yeah, you know your bandmate doesn't know how open source works

So, yeah, what you're asking about is really highly frowned upon I would say. Of course you're free to do it, but it's not something people actually do or something that goes in this community.

On the other hand, this is such a MAX thing to think and do, and if you want that I'd really suggest you worked with that. People over there sell externals, patches and MAX is better at making apps that are actually just patches.

What Pd people do is ask for donations. I do have a patreon by the way
https://patreon.com/porres

I've been doing cool stuff that people really use and find it useful and never thought I could charge for any of that and, of course, I can't live and base all the work that I do with Pd based on how much I make with Patreon, it's not for this that I do what I do... Pd is more about sharing, contributing, doing voluntary work and being "free" (as in speech, not as in beer).

What people that use Pd also do is create an app with libpd or something, do stuff that is based on Pd but it's a standalone thing on its own, and you can sell it in an app store or something...

Check for the license though. Pd's license is permissive, but most etxernals will use GPL, which won't allow you to sell. On the other hand, my stuff has a very permissive license and you can "do whatever the fuck you wanna do" as one of the clauses will say.

All I'd say is, if you make work and you get money and you use my stuff a lot and you like my work and you feel like motivating me, consider donating something via patreon.

I'm not saying that's the case for you exactly, I'm just telling how I stand on all this as to give you an example on the matter.

cheers

etxernals will use GPL, which won't allow you to sell.

This is not how the GPL works. It allows commercial use so you can definitely sell any such products.
However if you are distributing these products to users they have the right to see the source-code (as per the GPL).

they have the right to see the source-code (as per the GPL).

The source code of the externals or the pd patch one?

Definitely take care with license issues when distributing someone elses code. This kind of due diligence is often omitted and can cause issues down the line.