BOGO
buy one, get one

BOGOF
buy one, get one free

buy
to buy for cash

buy back
resgatar

buy in
abastecer-se de

buy into
comprar ações de

buy off
subornar

buy out
comprar a parte de

buy over
subornar

buy up
comprar

buy-in
compra

counter
to buy something under the counter

for
...he couldn't buy the car for want of money

fund
to buy funds

governor
shall I buy you the paper, governor?

impulse
impulse purchase / impulse buy

instalment
to buy on the instalment plan

match
...going to buy a coat and trousers to match

never-never
to buy something on the never-never

off-the-shelf
to buy something off-the-shelf

outright
to buy outright

pig
to buy a pig in a poke

retail
to buy retail

second-hand
to buy something second-hand

song
to buy something for a song

tick
to buy on tick

trust
to buy on trust

understand
...want to buy the house?

wholesale
to buy wholesale