Bargain a lot (4)
(Other definitions for great deal that I've seen before include "a lot" , "Bargain" , "plentiful supply" .)
I believe this is a double definition.
'bargain' is the first definition.
(synonyms)
'a lot' is the second definition.
('deal' can be a synonym of 'lot')
(Other definitions for deal that I've seen before include "bargain > timber" , "Treat" , "Distribute cards or do business" , "Softwood - business transaction" , "Give out (cards)" .)