Is this a good plan to get my ex back?

Build the relationship back without the gifts, because it could look from her perspective like you are trying to buy her and you really need to think about that............you wouldn't want to win her back by giving her these things only to lose her again in a couple of weeks time or for her to stay with you because you bought her presents............it puts more pressure on someone buying them gifts and even if this is what you are normally like then gifts are not the issue, someting else went wrong otherwise she wouldn't be your ex.