@tjerman This issue is the ease of usage of Corteza. The amounts are currently used inconsistently in Corteza, sometimes Euro sometimes $, and it is unclear where to change it to make sure it gets done everywhere. When it comes to the business using Corteza, the currency very much matters. Just think invoicing, quotes etc, you can have business in the USA doing business the Europe. You need a way to create a consistent view of the potential revenues etc.
I would suggest to have an Amount datatype rather than using a generic Number, with some currency symbol rendering options. With the Amount datatype, there should be a global configuration for default currency. In any part that create quotes or pricing, there should be an option to specify target currency. etc.
Also to you point about relative values, I think you should consider having a Percentage datatype. IMO it will make it clearer on how to interpret the number.