A lot of money. A phonetic spelling of the french word "beaucoup" combined with a word starting with the letter "b" which is a slang term for money, thus creating a "fun to say" turn of phrase for a lot of money.
Jacob: The familys that live on Windfordshtienenshire Court sure do seem to be, quote & unquote...rolling in it, do they not?
Jolanda: Heck yeah, don'chu know? They all got boo koo bucks.