Por la compra de 4 unidades iguales o combinadas de los siguientes artículos, GRATIS el de menor importe

{ "offers": [ { "sales_reference": "001028015400329 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028015402002 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028015400337 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028015701346 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028015401954 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028015401970 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028015401590 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028015401582 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028016300460 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028017500076 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028016300650 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028015400675 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028031700132 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028016200025 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028015401475 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028017100745 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028015401467 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028017500068 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028016700248 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028017500159 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028015403141 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028016300783 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028017300857 ", "seller": { "identifier": "001" } }, { "sales_reference": "001028017202871 ", "seller": { "identifier": "001" } } ], "subsite": { "identifier": "supermarketHipercorStore", "parent": { "identifier": "supermarket" } }, "query_params": { "centers": { "home_delivery": "0130" }, "is_full_documentation": false, "is_include_offer_availability": true }, "query_list_get_method": "001028015400329___,001028015402002___,001028015400337___,001028015701346___,001028015401954___,001028015401970___,001028015401590___,001028015401582___,001028016300460___,001028017500076___,001028016300650___,001028015400675___,001028031700132___,001028016200025___,001028015401475___,001028017100745___,001028015401467___,001028017500068___,001028016700248___,001028017500159___,001028015403141___,001028016300783___,001028017300857___,001028017202871___", "delivery_get_method": { "delivery_type": "home_delivery", "center_id": "0130" } }