I bought a pass this year in lot P.
Two years ago I waited till the last minute & got one in XX. That was across the road just north of the stadium. It was kind of a ghetto area, but the official parking lots were dirt / grass areas and fenced in. There was plenty of parking in the hoods outside the fences - and I'm sure it was only about $10. But you were basically parking in someone's yard. I got the feeling that the whole neighborhood took advantage of selling their yards for parking.
Walk to the stadium wasn't horrible compared to parking on most SEC campuses. Getting out after the game sucked. Took forever to get out of the lot. I purchased parking again this year just because I felt like my car was much safer in an official lot rather than some hoodrats yard, and I didn't want to take a shuttle because I'm leaving Jacksonville directly after the game. Plus I was able to get lot P which is much closer & appears to be on the same grounds as the stadium.