There are many factors to be considered here.

1. Compare the cost: How much does 30% cost against the anticipated LTV (lifetime value) of your customer, versus the CPA (cost per acquisition of a customer) using "traditional" marketing like ads, or sales teams etc. If the 30% is less than or equal to the typical CPA to onboard a customer then you're winning either way. Nothing to lose.

2. Added value: 2 things that matter A LOT with marketing, social proof, and reputation. People buy from people. You've probably heard it before, but it is true. And if "experts" in the field have wide reach (following) and great reputation, then it's INVALUABLE. You will have a hard time getting to that stage from scratch. It'll just take a long time and lots of effort pushing awesome content. If it turns out the CPA is higher (See (1)) then it might still be worth it for the nod in your direction from the reseller (IF they're an expert and using their influence to sell your product).

And subjectively, 30% isn't a lot in my opinion. If you earn, they earn. If your margin is high (which it should be for Saas in general due to low costs of goods (aside from salaries)) then it's worth it in my opinion. Referral marketing is powerful, when done right...

I hope this helps!

Stefan