Volgadon is correct about 'posh', which was adopted into English before 1830, money (Appears in Old Bailey proceedings). It soon was applied to anything sumptuous, lush or 'classy'- typical reverse or inflation slang.
One of the quotations in the OED:

1846, From "Swell's Night Guide," "As I used to doss there sometimes, her nibs got sweet on me, and in course we did our reg'lars, and the dossing mongary, lush and posh."

This has been gone over before, with references, but it's impossible to run down these old postings.