You're closer to right than you might think. Our local Dallas ABC affiliate, WFAA, used to run a weekly "Let Me Speak to the Manager" show where manager Mike Shapiro would answer letters on air. I remember him grumbling once about that new Batman show costing a whooping $25,000 per episode. Actually, I just read someplace on the web that it cost an average of $75K per episode (probably more than Mike's heart could have taken). Anyway, there were 120 episodes total, so at $25K the entire series would have run a mere $3 million-- way under what the car sold for. Thus, if the eps did cost $75K (more realistic, I would think) the entire series would have cost $9 mil-- a bit over twice what Rick Champagne paid for the Batmobile last Saturday night.
BTW, I watched the entire auction that day and the Batmobile segment was really fun. It was practically like a Rolling Stones concert there were so many fans around. George Barris really had his day (in more ways than one).