The maths is straightforward. If an association charges USD 500 per year in membership fees and the member discount on award entries is USD 100 per entry, you need to make five entries per year to break even. Most agencies entering awards seriously will clear that threshold quickly.
The complication is that not every programme offers member discounts, and not every association membership covers the programmes you care about. Check the membership benefits carefully before joining: some associations discount only their own programmes, while others offer broader benefits across affiliated award schemes.
The Awardy budget planner separates member and non-member pricing where data is available, so you can calculate exactly how much a membership would save given your planned submission volume - before renewing or joining.