I'm with you, Joe.
Most "rebuilds" require just a cleaning.
When parts are needed, they're usually minimal.
O-rings I buy a ACE Hardware at a fraction of the cost of the "Specialist" suppliers.
"Viton" as a compound appears to be a mandatory synthetic for o-rings as set forth by who?, ...someone with the ability to effectively market the what?, ...the product?
Sheeesh, man.
Fear is insanity, as is a $9.00 o-ring for any carburetor.