1966 Batman cards are only going for $4 - $7 on various sites. See actual prices for 1966 National Periodical Publications Batman cards listed on eBay.
1966 saw the mainstream introduction of Batman cards worldwide. There were six individual sets produced and licenced worldwide which resulted in no less than 22 variations available.
Black Bat Series (painted images with a black bat on the front)
Red Bat Series (painted images with a red bat on the front)
Blue Bat Series (painted images with a blue bat on the front)
Bat Laffs Series (featuring images from the Batman TV series)
Riddler's Riddle Series (featuring images from the Batman TV series with a riddle on the back)
Macleans / Weeties / Krinkle Cards (promotion cards for these products)
Each of the above sets are available as produced by varying companies worldwide including Topps, O-Pee-Chee, A&BC and Scanlens.
Visit Batmancards.com for more info.
You can also check out CardboardConnection.com for a detailed look at the best Batman cards from 1966. They offer the earliest Batman cards, Topps released several different Batman sets in 1966.