Financial transactions are not inherently bad. They are one half of value transfer. In your case, a win-win situation.
If you believe that, then it will be true for you. Alot of things are free. If you plant a potato you can end up with a whole field of potatoes that you can eat forever, for free. And all the potatoes you don't eat decomposes back into the soil and makes the soil healthier.
Nature is fundamentally free and abundant and I can't figure out why our society isn't. Everyone around me seems to conclude that nothing is free though so maybe there's something I see that others don't, or there's something everyone else sees that I don't.
You could always live an AnPrim lifestyle and that’s fine (one of Kaczynski’s main points was that specialization in the abstract is incompatible with people), but there are more obvious reasons why more people don’t do that.