You aren’t telling a lie. Just don’t tell the counter person. I’m an FFL holder. Trust me. I’ve been at it 21 years.
Since you are an FFL, it's a whole different ballgame for you. Your advice doesn't really help since the law is completely different for you... And as as mentioned above, your advice is actually a felony.
Shipping and packaging is going to cost you $25 on handgun and $35 on long gun using ups. FedEx may be a tick cheaper.
Errr.. I'd be surprised, Are you saying you can ship a handgun for $25 as a non-FFL?. Handguns have to go overnight, and both UPS and FedEx will be charging you $50-90 depending on weight.
I've always just shipped guns via a gun store. I shipped my CZ pistol through Adventure Outdoors last year, and I think it was either $25 or $35. For a non-FFL having a gun store do it will almost always be cheaper, unless they are ripping you off.