What would be a fair price to offer on this 6ft gulf sign?

Single sided average is $600-800 these days. Add $300 if double sided.

I had 3 in worse shape last year and they went for $500-550 each.

...the easiest thing to do (for a common sign like this) is look on eBay to see what they've sold for...

I would say the 5-600 range. This is not one of the earlier, more desirable ones.

I just bought one a month or so ago for $400. Good shape too.

I agree with Paul, $600-800.00. It's a desirable sign. The older signs are worth more, simply because they are older and thus a little harder to find. Has nothing to do with desirability.

This one just sold for 7 hundred tuesday https://www.proxibid.com/asp/LotDetail.a...ELAIN-1965-NICE

Thanks for all the information, I will pass on this sign simply because owner thinks its way more valuable than it really is.

Good Choice