Selling a very rare album

Want to get your thoughts. I'm selling my album collection and I have a rare issue from Jethro Tull named "Hand in Glove" that only 500 were pressed according to disclogs and popsike. The album actually has paper glued on the front and back with Ian Andersons face with a slogan on the front and the song names on the back. It is a double album in mint condition. How would you determine or who would you ask how much something like this is worth?
It's a bootleg from an LA concert. Not much.
Maybe a limited press, but not "rare"

Only for the hardcore Tull fans, which are getting up in age. Hurry and sell it, before it's too late!
If you already checked and discogs for the price statistics then why do you ask ? 
If its a bootleg, you won't get much for it.  I bought a Pink Floyd bootleg called "Raving and drooling" from the Animals tour and it is one of the worst recordings I ever heard.  A tin can telephone has better sound.  I paid $40.00 for it, what a waste of money.  If anyone wants it, Ill let it go for $20.00, lol.  I purchased it from discogs.
That is true Greg, or sales of downloaded music even if it was an official release.

Just to throw my lot in, I also bought a concert bootleg by Rush on eBay.
Terrible SQ but as I have all of Rush output I wanted it but it will never get played again......
According to Gripsweat it is about a $50.00 album, tops.  If you can get that for it, you will be doing well. Not an artist that there is strong interest in these days.You might find one of his fan sites and see if they will allow you to post it for sale.
Yep, sounds like a classic bootleg, and if so, then you shouldn't be selling it on the open market.  Intellectual property rights and all that. 
I actually have a copy of this show on a CD.  I was big into bootleg trading in the early days before everything was downloadable on the internet.
I saw Ian Anderson about 7 years ago in Morristown NJ  My son called me up said hey Ian Anderson is coming to town let's go see him.
My reply was, You have no idea who he is ! As I remember my son running out of the room when I started to play Thick as a Brick :  )
Anyway we went. And Ian had absolutely no voice left, but could that man play the Flute!!
I was right my son really had no idea who he was, but he did enjoy the concert. There is hope
Bootlegs are best sold on fan sites of the actual artist. I would find Jethro Tull fan forums and go from there. Back in the day, Elvis Presley bootlegs were popular. Now that RCA has released everything under the son, including many soundboard recordings with their FTD issues, the values have dropped quite a bit. 
Discogs won't even allow it to be listed, presumably because of the questionable legal status of the bootleg.
Maybe you get more money if you gently erase "Hand in" and replace with "Smell the" instead. That way you would have Spinal Tap classic to sell :)
There is a legit 3 lp release of this that goes for about $100. 
Discogs does list bootlegs but they don't allow them to be offered for sale.
If you do list it for sale, make sure that the potential buyer knows it's of poor quality. A hardcore fan would want it anyway. I had a guy send me Gordon lightfoot cassettes years ago. He rated each tape by the SQ. Tapes that I could barely hear, he rated A minus! I don't think I even tried to listen to a tape he rated a B minus. Most bootleg records are of really crappy quality.