I still disagree with you and in fact, you are disagreeing with most of the people here that have advised you. You most likely have gear lust and a hole burning in your pocket. Hey, I was once like that too. Nothing wrong with it! 
The bottom line is you are just getting started and you are new to this. Everything is relative too and the weakest link in the chain brings everything else down. You should really assign a line item in your budget for treatment. Here’s why:
You are an aspiring musician and recordist. Sound needs stable environment to gather in order to listen critically and make good judgment calls. When you are able to listen critically, you will be able to discern more qualities in the sound that you are mixing and recording. In doing so, being a self recorder, the nuances of your performance will be further exposed. This will bring an awareness that should lead you to optimize your voice for instance:
“Wow, I really hear my lisp when I sing that way.”
Then you will alter the shape of your mouth next take and draw closer to what you want becoming a better singer.
Apply the same to mixing. And don’t rule out: the room you mix in can also be the room you record in too.
Well, that’s all I have to say on this. I will always disagree with anyone that has a startup budget that says there isn’t enough money for any treatment. That is BS BS BS considering how inexpensive a duvet is at a goodwill on up to mineral wool or compressed ridged fiberglass and burlap to store bought ready-made panels. Sure, gear is sparkly with ooh ahh… drooooool… but there is so much to gain with a stable environment.
I said and still feel you are naive because you took one single and very important piece of advice and threw it out the window with: it’s cost prohibitive to ‘the project’. The advice was given by many different people, some with many years experience, like myself, all on their own time and right on the mark in my opinion. Now go and buy what you see fitting to the ‘project’ and don’t even think of any acoustic treatment! 