ETL mics can sound good from what I've seen, but they are clearly meeting a kind of look market, as well. Folks like them, and it wouldn't put a huge dent in your budget to have one laying around for the vibe
. I've seen them used more in places where the gain could be turned up without inducing feedback, i.e., not an amplified, inside venue.
But, if you want to record multiple sources with a single mic, whatever you do is going to be a compromise. Get a good mic and start working on technique. Anything from Shure, AKG, AT in that $1k range should be fine, TBH.
[curmudgen-mode]I spent part of last year trying single mic recording with guitar+vocal. It's a PITA, IMO. Very, very sensitive to mic position, singer vs. instrument levels and then everything else going on, because you've generally ruled out close micing. Really, I don't get it... [/curmudgen-mode]