what you have been offered is more likely whole motherboards that still are populated but have just had the memory and the CPU removed. That is standard in the industry. We all keep the CPU's and the memory and sell the rest of the motherboard for parts or for scrap.
I have inserted below a recent price list that shows what someone offered to purchase my stream of e-scrap for. High grade circuit boards would be the motherboards and the video cards, etc. The low grade boards would be pulled from scrap monitors and printers normally. If you can find a buyer for the boards and then negotiate a better sale price with your source you may be able to make more money than if you attempted to process the boards yourself. You wouldn't have to risk working with the chemicals either.
Ask for a picture of the boards and see what they look like first - you know "caveat emptor"!!
MONITORS
14" $1.00
15" $1.00
17" $1.00
19" & UP $0.00
SCREEN BURNED MONTIORS .18 CHARGE
TV'S/ TERMINALS .18 CHARGE
COMMODITITES
HIGH GRADE CIRCUIT BOARD $1.85
LOW GRADE CIRCUIT BOARD $0.06
ALUMINUM BREAKAGE $0.06
CLEAN ALUMINUM $0.10
STAINLESS STEEL CALL
SCRAP COMPUTER PLASTIC $0.00
KEYBOARD $0.01
MICE $0.01
SPEAKER, FANS $0.01
PRINTERS $0.01
UPS $0.01
HDD $0.35
FLOPPY DRIVE & CD-ROM $0.06
POWER SUPPLY $0.13
TRANSFORMER (SMALL) $0.08
TRANSFORMER (LARGE) $0.08
MOTOR $0.04
WIRE/CABLE $0.35
COPPER YOLKS $0.15
AC ADAPTERS $0.05
MAINFRAME CALL
SERVER/MEMORY/CPU $0.12
COMPLETE PC $0.16
INCOMPLETE PC $0.12
MIXED SYSTEMS $0.08
HUBS, ROUTERS, MODEMS $0.08
AIR CONDITIONING UNITS $0.00
LEAD ACID BATTERY $0.07
RECHARGABLE BATTERY $0.10
BALLAST (NO PCB) $0.05
MEMORY MIXED $3.50
MISC ELECTRONICS $0.01
HOUSEHOLD ELECTRONICS $0.00