Selling an upgrade like 200Amp panel VS 100 is ok. labor is exactly the same but they pay little more to get the 200Amp.
A suggestion on a ceiling fan, new circuit new lighting, GFCI for the appropriate locations are O.K. to sell. But do not screw people by installing a GFCI in an bedroom,by installing a 200Amp service for a 800 sqft condo...
That is all i am saying.
A true sales person will not screw the consumer. But sell what the consumer needs upgrade to the existing condition either cosmeticaly or for safety.
Edward