All domains are end-user based in value -- with the possible exception of domains with significant parking revenue ... such that they would never need to be sold or even developed. Even a domainer assesses the likelihood of various end-user amounts and then offers a lower figure to leave some room for profit. I know what you mean, I think -- which is that it's hard to predict.
Nice domain name. I agree it is a hard one to put a price on, but I can see it selling in the $1500 - $2000 range. After all, everybody likes a Back Linker
If I were the owner of this domain name I would add some value to it. There is great potential but some buyers don't want to start from scratch. I'd add some unique content or hire a VA to do it. Do a few back links, do a few youtube videos to get the traffic up, and have an adsense account. If you want to add a aweber account to try and get a list started for when I sell it that could be an additional feature to drive the price up. Then I'd wait at least 3 months to sell it on an auction.....IMHO Good Luck!
In case anybody is interested (or knows somebody who may be interested) Back-Linker.com is currently at auction on Flippa.