Yes you will have it at the end of the show as long as submitted before whatever cutoff they set. And it will cost $20 plus $10 handling (they have that $10 fee on every invoice regardless if sent to PCGS or done at a show).
There's no scam at all and grading is the collectors best friend. Dealers call it a scam because it makes it harder for them to take advantage of collectors If thats the going price of an item than that is what that item is worth regardless of what people online THINK it should be worth. The market sets prices, not forums