Translation:I have salt and you have pepper.
Is it not true that 'saya' and 'kamu' should not be used in the same sentence? As 'saya' is the formal version of 'I' and 'kamu is the informal version of' you'. Wouldn't it make more sense to use 'Anda' if you were using 'Saya' and 'Kamu' with 'Aku'.
if we talking strictly in formal situation, eg. formal letter or business meeting, we must use the formal version.
It's a little bit different when we are in conversation, sometimes we can mix the formal and informal. Also habits have its parts too, eg. use "Aku" means to humble oneself and "Anda" to respect the opponent.
But for education purpose and less confusion, i agree they shouldn't be mixed