[Unbound] So... How good is the idea to buy DLCs or Ultimate collection upgrade?

Started playing a few days ago, right now finishing the first week of the story and I really like the game. Started playing it right after Heat and honestly I like Unbound a bit more. So my question is - how reasonable it is to buy DLCs or Ultimate collection upgrade now? Do you only get cosmetics and new cars from it? Can I get these things without buying stuff? Thanks