Okay, so apparently there wasn't an extra lens. She thought I meant filter. There are a few filters though, an extra back, a 75/2.8 lens, a non-metered prism (which is fine; I got a Minolta Flash Meter II for $4), a couple SunPak flashes and remote eyes, a speed trigger, and a couple pelican cases for it all. It was all in pristine condition (except the leather on the speed trigger is coming apart a little). Got it for $250.
On another note, I found a Polaroid SX-70 Sonar OneStep at Goodwill for $20!