Don’t think it will be a huge crowd Fluffy. 32,000 I reckon. The cheapest option is to just turn up on the day and buy general admission tickets, which will get you into Level 3. If you get there at least 45 minutes before the game, you can get front row seats, or near enough to. You can then pick and choose where you want to sit, without too much hassle. Pretty good vantage point, which gives you a really good view of how the game unfolds.
If you really want to sit on Level 1, you will need to pay extra for the privilege. Ditto Level 2, plus a bit extra. Might be worth asking when you purchase the tickets, but I'm pretty sure it's more than a tad dearer if you want to pay for a seat.
Enjoy your stay Fluffy, if not the game. Hope it’s at least a contest.