changes in an existing laravel project -- 2

i have laravel project and need some changes in it. the project is a point of sale,inventory and accounting project. changes as mentioned below:- 1> i want to add some feature like schemes such as buy two get one free or buy 2 get a product free or buy products of certain amount and get some discount or product free. 2>Product Purchase entry through excel. 3>MRP and discount on bills example: total saved amount should be mentioned. 4> In product purchase entry total quantity, total amount without tax, total discount should be mentioned. 5> GST reports 6> one more subcategory option should be available. 7> schemes and discounts should be autoclosed after a certain mentioned quantity of products are sold or products of a particular purchase are sold. 8> Logs of add,edit and delete should also be made available. 9> a custom invoice format is required which will be described. Project will be awarded to the lowest bid with highest experience.