I'm a training monster. I eat it up. I get it wherever and whenever I can. I support anyone in the DFIR field to get as much as they can too. If you are in government, you get more than your share without spending a dime out of pocket (sorry for the private sector folks, but you guys get to pay for the public sector expenses for training). I love conferences too. I've been to more than I can remember. I can look at a map and point to dozens of places nationwide where I attended a course or conference in just as many different states and cities.
I have presented a lot too. Some in public, some in unmarked buildings. For the unmarked buildings, I get paid because I am technically working (it's this thing called a salary). For the public presentations, I did it for free on several occasions, for giant corporations that paid me in free bagels and coffee for breakfast. Oh yeah, I got "free" tuition in the conferences too. Everything else was out of my pocket.
<hopping on soap box>
I stopped presenting for free. I recommend that you stop presenting for free. For every free presentation I did, my out-of-pocket included door-to-door transportation to the event (taxi, airfare), hotel, meals, incidentals, hours of preparation, and days of burnt vacation hours. After seeing a thousand attendees who paid $2K to attend conferences, where everyone was paid except for me (caterers were paid, live band was paid, open bar was paid, and I am sure the dancing bears were paid too), I had an epiphany: I should be paid too!
My point is that for the huge corporate events where the gross revenue is hundreds of thousands of dollars (or over a million), I am certain that the organization can float a little to the presenters. Especially since the attendees pay $2000+ to listen to the presenters. Really, the presenters are the glue and fabric to any conference, yet the vast majority are not paid. They volunteer so much for a line on their CV, in which the organizer takes advantage of.
Here is a secret: I still present at conferences. I present at the same conferences where I volunteered to present for free. The difference is that now I get paid. The next time you are recruited to present for free, I mean, in exchange for a bagel and coffee, offer to send an engagement letter with your fees. Either they pay or they won't. If they really want you, they will pay. I promise you, they will pay. They will pay for door-to-door travel, airfare, hotel, meals, and for your time. If they don't pay, it is not because they do not have money, it is because they can find a sucker to do it for free, I mean, someone who wants to write a line on their CV for presenting. Also, don't be shy on what to charge. Business class is not that much more expensive than coach. Hotels are fairly inexpensive no matter where you go, and meals are meals. The point is that when you spend $2,000 to teach for free + burnt vacation time, you lose. That's an expensive line to add to your CV.
Another little secret...if you are presenting for free, you have other presenters at the same conference getting paid. Their travel, lodging, meals, and time is paid. Yours is not. Theirs is. You may even be better known than the paid presenters, but there is one huge difference: The other presenters required payment for services rendered and you didn't.
Exceptions: You know that not-for-profit DFIR associations and groups, you had better present and volunteer your time for free. That's where the real networking is. That's where you can meet those who are digging into every crack and crevice to learn and meet people. You'll find the DFIRrs that work in buildings without windows as well as those who work for big name brands. These groups aren't making money. They are making great events. Don't diss them and charge for your time. Help them grow. Now...in regards to an organization whose gross QUARTERLY revenue is $30million....they should pay.