While the graphics on this sign are great, the condition is poor. Many serious collectors would pass it by unless they needed the lollypop stand for a 30" sign they already have.
Putting a value on it is difficult because you have to match it up to a collector who willing to buy a sign in poor condition. Much easier to find a buyer for a sign in nice condition.
I recommend that you try to polish the better side of the sign with some automotive rubbing compound or polish. Clean it and then wax it with auto wax.