Not really, magento loads the config in to memory for stores as well as websites. Although you are looking at the technical side there is also the business aspect. If you need different checkout currencies you need to use website pricing (we have licensed a dynamic pricing solution but that is another matter), each website base currency for each product then has to be adjusted manually. If you perform currency updates you have to reload the entire product dataset otherwise they become out of sync, visitors do not like checking out in non-native currencies. Another example is that carts are cleared when moving between websites, this is in Magento core. Unfortunately some of the comments do not understand the concept of international sales, which is why not many small businesses succeed at it.
Whether to create a website per country, or a website per base checkout currency, or one website with multiple stores comes down to business requirements and that is a consulting job which cannot be advised on sparse information. One of the key aspects is you will need better hosting the more websites/stores/products/categories you have, the guide is 0.5-1% of revenue for the hosting.