Hi @Massi. You can combine Level Aware Calculations to achieve what you are looking for. The two calculations should be what you are looking for.
Avg Daily Purchases Amount per User =
avg(sumOver({PurchaseAmount_Clean},[User],PRE_AGG)/sumOver({Daily_Active},[User],PRE_AGG))
Lifetime Value =
avg(sumOver({PurchaseAmount_Clean},[User],PRE_AGG)/sumOver({Daily_Active},[User],PRE_AGG))
avg(sumOver({Daily_Active},[User],PRE_AGG))