Hey Brian,
There is definitely value in setting up REW and measuring your room, and certainly not a bad idea to do so before buying a BFD (even though they're relatively cheap).
Once you measure your response, you will have an idea of how "bad" it is -- or it could be good just by happenstance. Could go either way. It's definitely fun for me, but I like that kind of stuff.
I know that the setup seems like a lot, but it's not really that bad once you get going. Give it s ahot!