As a SoCaler, I’ve been going to KSF every year since 2009 and I never once bought the fright lane. The night you are going is going to be pretty packed, but if you mainly care about the houses, you can definitely knock everything out, even if you’re going for GA and go on a sold out night! Strategically, the best option is always to come early and go for the houses in the backstage area by Ghostrider and do Paranormal first, Wax Works, then do the last two.
Now I’ve never done prescare (I want to some day!) but for another $45, you get all you can eat food, one complementary alcoholic drink, and EARLY ENTRY to the four backstage houses! They’re the ones you want to do first anyway. I’m pretty sure they operate an hour before rope drop (7PM) so by the time you knock ‘em all out, you can make your way to the back! Do Origins, Mesmer, then Dark Ride. By the time the lines will start to grow, you should only have two houses left to knock out and you should be done with houses by 8:30! From then on, you can chose to watch a show, wait in line for a coaster, or revisit your favorite house....with a line of course.
Gun to my head, if you were to ask me “Prescare or Fright Lane”, I’d go for the prescare. You get a LOT of good food and you get an hour head start on half of the houses! That sounds like an excellent value to me. If you care far more about wanting to be able to cram in the coasters as well, then Fright Lane. But I would seriously consider prescare.
Oh and don’t miss the Log Ride! Sadly, they no longer have scareactors on the ride during the event, but it’s a great overlay for an already great flume ride!
Hope this was helpful! Have fun!