Mozzarella

I sent email "feelers" to several universities asking about PhD assistantship positions in Food Science (chemistry) for the upcoming Fall Semester and I just received an email from a professor asking if I would be interested in visiting the campus to meet and visit the lab. Is this typical to get an "unofficial" invitation like this? He mentioned he was just starting to review applications so it struck me as odd. If I am accepted, doesn't the University pay for my visit? The University is quite far away (7 hours by car); I am willing to travel and visit to improve my chances of getting accepted, but I also don't want to get suckered into paying for a visit on my own dime when the university typically pays.