Welcome to Boardsort™ - Learn - Sell - Profit -

32 - top two or left two would be GFC, better rate if you remove plate.
The others are prob low perif, but still remove plate
31 - Take them out of plastic, typically Telco
30 - would think perif high, back is basically blank
29 - I would pull the plated mini connectors on the back, the board I think is perif low either way
28 - Too much heavy junk (transformers, large caps wiring), as is thinking low if they would buy it at all. W/O big Junk prob lo-perif or mid.

I agree.

32) Remove the metal plates on the two boards with the longer fingers for Clean Gold Finger Cards. Remove the metal plates on the other two for High Grade Peripheral.
31) Like sail4life said, you need to remove the covers and repost.
30) High Grade Peripheral
29) Low Grade Peripheral
28) Low Grade