(Some corrections have been made)
An offering is not compensation for sutras.
“Observe” is one of the “works of wisdom that benefits people (Hannya),” along with “saying kind words (love language),” “helping people in need (Toshiyuki),” and “thinking with the other person's feelings (colleague).”
Are good deeds compulsory? Isn't it something that comes from nature and the heart (event)?
I'm giving the answers here for free. But this is thanks to my parishioners preparing a temple, and I have enough financial power to eat.
How would you say thank you for your answers here? There is an “Okimochi” button. Not all of the money for the Okimochi button will be delivered to me. It is used for the operation of hasunoha. (Donations from other charities, etc.) If hasunoha is properly managed and the charity thrives, many people can be saved. I think being kind to others would also be a thank you for being kind to me. People who have been treated well will also be kind to others. As a result, there are fewer hasunoha questions, and I am saved. Of course, the same goes for offerings to the temple of the family. The temple will use that money with care, and someone will be saved. Then, it goes around and comes back to you.
As you can see, the money flow ring and the good deeds ring go round and round in different places, but it's not good to stop them both along the way. If you say, “If it's not compulsory, I won't do it,” the economy and good deeds will stop flowing. If the flow stops, it won't go to anyone else's place, and results will be created that won't go back to you.
By all means, I think it would be a good idea to properly hold the Obon and Ohigan memorial services and pay the offerings. It's not compulsory, but it's my duty as a Buddhist.
That said, I think the temple you're asking about is a bit overkill, but don't be too stubborn.