I cant fuel my car more than 1 gallon without taking a break. I took it to the dealer, they diagnosed it as a clogged charcoal canister and says repair will cost around $950

Can someone point me towards the right direction? Called a few autoparts stores they claim thats a "dealer only" part. There has to be another way.. I'm open to any options!

Thanks,

LiSolo

EDIT: I was told by the dealer the vehicle needs a new charcoal canister which is needed for the evaporative system with the fuel tank. The canister would need a new valve and wiring harness due to the fact that the canister is an updated part.
203-470-03-59 ACTIVATED
000-470-71-93 VALVE
211-440-01-34 CABLE HAR

EDIT 2: I think I found the original part:
Mercedes Benz - C320 - Purge Valve - Vapor canister - 0004701593
Can any one confirm? I'm assuming since its unmodified I wouldn't need the other two items?