what I'm about to tell is based on instinct only!!! be warned. ;)
(well it's a little based on the rules as well)
PR man: I don't think he will influence a lot on merchandising, in the rules it says that people want to buy winnig team's stuff. Merchandisisng probably is depending on the league and your wins, and MAYBE a little on PR, but I doubt it.
What I thing PR does is this: influence your fan base. this means you will sell more luxury boxes and courtside seats, these are the more steady numbers, and are in my opinion strongly influenced by the PR man, and a littel by your wins.
The other seats and bleachers are for the people who will come if you win, so the PR man will only be of little influence on them.
So in order to see the effect or the PR man, I think you should look at luxury boxes and courtside seats (given that you don't chance the ticket prizes!!!)
That's what I think, it could be horribly wrong though...
I do bleieve that if you want to build up a steady growing fanbase, you should have some degree of PR man, so it is more a long term investment. If you are only interested in short term, you might as well hire a level 1.
I truly can't tell if the long term plan will be more profitable though.
They are not your friends; they dispise you. I am the only one you can count on. Trust me.