Not to get in the way of the pissing match...
Back to the subject at hand & To the OP's question. I think a better interface with a great internal pre
& a better mic would be a better bet.
Something like:
An APOGEE DUET for $500 will give you a much better A/D D/A and a really high quality pre.
Plus.
A Shure SM7b for $350, a Blue Dragonfly for $600, a Shure KSM32 for $500, a Blue Baby Bottle for $500 or any decent mic you like for $500.
It depends on your voice and your preference. Head to a music shop and demo a few in the $500 range & pick.
IMO that would serve you much better.