While I do think this could be a good idea, I would, personally, be uncomfortable taking money in any form. My belief is that dmt is to be shared without expectation of restitution or reciprocity. That said, you may have a different point of view, and I can certainly see ways around my moral objection (eg not asking for money for the aya ceremony, but if guests were to stay in some form of accommodation some form of restitution may be in order).
There's also the point of experience. In my mind an aya ceremony should only be conducted by someone very well experienced with the brew, the experience and the spirituality that come with it. I'm not sure how familiar you are with aya, but I know myself, even having participated in ceremonies and used it on my own many times, I'm not very comfortable giving it to others because I know I've had bad experiences with the stuff and I don't want to subject others to the bad ones.
But that's just my opinion. I think you should be careful, but if you're comfortable with these issues and you execute your idea well it could be fantastic.
"Laws alone can not secure freedom of expression; in order that every man present his views without penalty there must be a spirit of tolerance in the entire population." -Albert Einstein
I'm not a big fan of SWIM. I mean, I've never met the guy, but any time I hear about him, he's doing something sketchy.