Since just about everyone is expanding by almost entirely just bleachers, i decided to check out how much the top 25 arenas are worth (from how much it takes to build each type of seat) and then divide that by the number of seats to calculate who was spending the most/least on average per seat to expand.
Total Arena Value rankings:
1. 7,520,600 - Salisbury Auerbachs (NBBA)
2. 6,490,000 - nth_mlb_giants (NBBA)
3. 5,427,500 - LCD Celtics (NBBA)
4. 5,386,000 - Chicago Bulls (NBBA)
5. 5,154,000 - King Drive Ballers (NBBA)
6. 4,730,500 - Demon Hoosiers (NBBA)
7. 4,730,000 - Bruins (II.1)
8. 4,562,000 - Ice Storm BC (NBBA)
9. 4,519,500 - Wake Forest (II.2)
10. 4,019,300 - DC Dribble Penetrators (II.2)
11. 4,003,000 - Raleigh Roughriders (II.3)
12. 3,872,500 - NY Wahoos (NBBA)
13. 3,750,000 - Fort Worth Flyers (II.2)
14. 3,748,000 - Orlando Rush (II.4)
15. 3,735,000 - Red Sox Nation (NBBA)
16. 3,640,000 - Burlington Mountain Goats (NBBA)
17. 3,626,500 - The Fish That Saved Pittsburgh (NBBA)
18. 3,597,000 - Turkey Sandwiches (NBBA)
19. 3,465,500 - Inland Emperors (II.2)
20. 3,261,600 - PackerBackers (II.2)
21. 3,197,400 - Phi Slama Jama (NBBA)
22. 3,190,400 - Walking Through This Door (II.1)
23. 3,095,000 - Roosevelt Raiders (III.3)
24. 3,022,000 - I'll Replace You With Machines (III.10)
25. 2,988,500 - Marietta Magic (III.11)