It isn't that out of touch with contemporary prices. Maybe 10 years at most, as a lot of the cost increase has been the past 5 years. Doesn't mean the image isn't older, just commenting on the price here.

A current restaurant serving Lobster Thermidor costs about 55$. While any place serving this dish is likely a high quality restaurant, it's not until one obtains a michelin star that it becomes a 3 digit affair.