I've only just started playing TD2 this week with the upgrade. Is the RE event/outfit achievable for me? Or is it a mid/late game thing?
So I don't have the answer to that question, unfortunately. I've had the game since launch but bounced off within 2 weeks, and deleted my old character, so returning to it now, I started from scratch too.
I have no idea how you get the event done for free. I ended up just moneyhatting the event by doing my first microtransaction purchase in Division 2 -- I grabbed the currency bundle that's a one-time promotion and nets like $35 worth of in-game currency for only $20, then just used the in-game currency to buy my way through the entire event.
If you end up going that route, it's worth noting that it seems that you cannot get duplicates if you just moneyhat your way through the event like I did. Never once popped a duplicate and "finished" collecting all of the event items well before I ran out of currency, so I have like $11 worth of currency leftover for later.