These are listed in Chadwick's OK book as $75 for the 25¢ one, but the 50¢ one is not listed. There are also 5¢, 10¢, and $1 shown. If I were you, I'd eBay them one at a time with a few weeks in between. Don't start the bidding at too high of a price - say no higher than $19.95 - and let the market find their value. Assuming the book value is still as good as a token rarity ever is, the market will become saturated after a while. I imagine there are only a few real serious OK collectors out there - they will get the first few and the price will be high because the serious guys will bid them up. After the first ones sell, then the "bottom feeders" will start bidding, but the selling price will start going down.
John in the Great 208