Does it seem less "professional" to send a package by USPS instead of fed-ex?

I often have to mail things to reporters. But I work for a non-profit, and sending fed-ex is expensive. Aside from the fact that USPS takes a lot longer, does it seem less “professional” to send things that way? When I receive a fed-ex package, I open it right away because i assume it’s important…but the question is, if I were a reporter getting lots of unsolicited mail, would the USPS envelope sit at the bottom of the pile? Our organization doesn’t have a lot of money but it would be worth spending more to ship it if it means the package gets opened and draws more attention.