For reference:
Green dirt - 6 cargo, $6
Purple dirt - 4 cargo, $4
Three orange diamonds- 47 cargo, $47
(I see a pattern, here...)
One black square - $8
Two black squares - $12
Two green diamonds ("\" arrangement) - $100~110
Two green diamonds ("/" arrangement) - $86~103
(I gave up once I realised there was some price variance)