It takes a bit to get up to speed, so don’t be deterred.
While I do not recommend eyeballing a deal as a substitute for gathering inputs and running an accurate calculation, sometimes it can help with a brief sanity check.
This 330i was a loaner, so by nature it should be lower than new unit, but take a quick look (you’ll have to look at the edit history to see the price).
Also, and I don’t know if you’d even want a 530i, but directly below that you’ll find one priced more attractively than the 3 you came to ask about.
Purely from a sanity check perspective, I’d say your original deal is weak, but definitely dive in because understanding in detail why a deal is weak or why it’s strong has similar educational value.