I've got a handful of those Bally operator price lists that show up on eBay occasionally. Fun to look at and interesting to consider the costs in today's dollars. Using an inflation calculator on the US government BLS web site, here are the "then and now" prices:
Miami Beach: $775 in 1955, equivalent to $6,970 in 2016.
Night Club: $785 in 1956, $6,956 today.
Double Header: $799.50 in 1956, $7,084 today.
Carnival Queen: $902 in 1958, $7,523 today.
Laguna Beach: $1,075 in 1960, $8,753 today.
It shows the pricing power Bally was able to command by developing the magic screen games. The first three (non-screen) games retailed for approximately $7,000, while Bally was able to jump the price point up to $8,753 (in 2016 dollars) by 1960, a nice 25% increase. Good for them.
Bally_Price_List_1955-09-10_Miami_Beach_(resized).jpg
Bally_Price_List_1956-03-15_Night-Club_and_Crosswords_(resized).jpg
Bally_Price_List_1956-08-01_Double_Header_(resized).jpg