Help me choose my unit size

To see which unit sizes are currently available:

4 x 6 -or- 5 x 5

$35

5 x 10

$45

6 x 12

$63

5 x 15 -or- 7.5 x 10 -or- 8 x 9.5

$65

10 x 10 -or- 8 x 12.5

$90

9.5 x 12

$95

11 x 12

$100

10 x 14 -or- 8 x 17.5

$115

8 x 21

$120

10 x 18

$125

18 x 12

$130

10 x 24

$145

10 x 30

$160

13 x 24

$170

15 x 24

$195

16 x 48

$340

18 x 48

$365

24 x 53

$500