You’ll need about 15–25 Mbps internet speed to stream HBO Max content in HD. The New America Foundation indicates the average price for 15–20 Mbps internet speed is about $41.95 per month.
If your internet connection is on the slower end (think DSL), you might find that HBO Max will end up costing you more than $14.99 per month because you’ll need to upgrade your internet service to get a good streaming experience.