For a downtown ballpark, parking at Coca-Cola Field is surprisingly reasonably priced. There are a number of options for both covered and uncovered lots, usually for $6 or under. You can park directly across the street from the ballpark in the large lot beneath One HSBC Center for $5 on game days. This lot is covered and guarded.
As you circle the block around Coca-Cola Field, you’ll see some lots of signs that reference prices of $8 or $10. While you may be tempted to park here and get to the game, continue driving around until you can pay in the neighborhood of $5.