If you try eBay you may get $15 to $20 but it most likely wouldn't sell as there's no real market for blends especially non aged, remember you're not selling the whisky just the bottle. At the last whisky auction in Scotland blends were not making more than £50 or £60 and that was for 4 or 5 mixed makes.
I know Craig said it may not be drinkable and no one would know until it's opened but that's my recommendation. It has a KnS seal which were pretty air tight in their day and there doesn't appear to be much evaporation so the main problem would be from the cork liner to the cap or oxydation from sunlight, but the colour looks good. All in all I'd say have a dram, if there's a slight bitter taste then it's oxydised and once emptied use the bottle as a lamp base which is what most of these bottles were used for once they're emptied back in the 50's and 60's.