1.- Before purchasing, make sure that Filmora is the best option for you. Consider the pros, cons and your budget (read my full review here), just because there is a discount, it does not mean you have to buy.
2.- Be strategic, some options without a code can be cheaper than one with code, for example, Filmora has versions of its page in many languages that feature a more affordable price, such that, a 15% discount for that version can be cheaper than a 25% with the English version (even though they work on both).