#1
I have a Line 6 FBV shortboard:
http://www.tonika.nl/shop/imagesgroot/FBVSHORTUSB.jpg

And the pedal has gone to crap. What I mean is that it wobbles excessively and won't stay in position anymore, so pretty much I can't leave the volume or wah at a certain level because it doesn't stay still.

I took the back apart and saw there was a nut to the side of the pedal, and I tightened that, but all it did was turn this other metal piece across from it in unison. So then I saw that metal piece had a hexagonal shape for a 3/16 inch Allen wrench. I turned that while using a pair of pliers to hold the nut. I tightened it and a plastic washer snapped. I then tried taking out the nut and putting in tiny rubber bands, but that did nothing. I'm running out of ideas. And I don't have a warranty anymore.

I was thinking of doing 1 of 3 things.

1. I found a repair shop that would fix it, but the minimum bench fee is $35 and it can only be that if it's a small fix. The problem is, I'm in college now and the only way to bring it to the guy is by cab so I would be spending $10 each way to get there, plus the $35, and then $10 each way when I'm picking it up. So that'll run me $115 at least for what I'm thinking is a minor fix. (I might avoid the cab issue if I had my mom or someone come up to visit and take me when they're around.)

2. Or I was thinking of selling the shortboard as is on craigslist or Ebay. The only problem is the pedal wobbling, the functions still work, and one LED light went out but the button itself works. Would it be possible to sell it given that I can't find any other similar sales online on those previous websites? (Well at least, I can't find any broken pedals so I don't know what's a reasonable asking price.)

Then with that profit, I would buy the new version that came out: http://www.long-mcquade.com/files/6786/lg_shortboard.JPG

3. Go from music store to music store, and find a guitar tech that will tell me how to fix it myself or fix it for a cheaper price than what I found before.
#3
You need to take a pic of the pivot mechanism to be able to give you any ideas of a fix. It would depend on how its put together on what kind of parts you could use to fix it.