It has been awhile since I submitted at a shows, but the cost per coin was higher than sending them in.
Only if you do show grading. You can also submit for regular grading where they will take it back and grade it.
I have more than 5 coins and I am a member of ANA
How many and of what. You can actually get a discount on your submission charges if you join the PCGS
tier with 8 vouchers. That membership is $249 and you can get $320 in value with a regular gold shield submission level for them. You also get a free shirt that you can sell for $15-20 if you don't want it making it an even better deal.
I'd rejoin every regular level submission if I could