Yo EV! This question has been asked, and answered, so many times I have nightmares about it. Short form- The needs of recording voice and acoustic are rather different, and most people simply don't use the same mic for those two jobs. You can mic an acoustic with one or two small diaphragm condensers, one or two large diaphragms, or one of each. Dynamics, which are often OK for vox, are rarely chosen for acoustic guitar. Generally, acoustics require high end detail, sensitivity to fast transients, and some bass rolloff is good to decrease boom. That prescription will make most singers sound like a cat in heat, unless they are very good. Cheap guitars often profit from colored mics, which provide the selective distortion we call "warmth", which basically provides less detail, airbrushing the rough edges of an inexpensive guitar. The same can be true of vocalists. You don't need to airbrush Pavarotti, Charlotte Church, or Freddy Mercury. And I don't think I'd use a reference mic to record No Doubt.
So- You have to ask yourself just what kind of guitar and voice you intend to record. Ovation, or Huss and Dalton? Epiphone or Breedlove? Washburn or Froggy Bottom? Ibanez or Martin? Same thing with the singer. Dolly Parton or Juliana Hatfield? Bob Dylan or Garth Brooks? Ray Charles or Meatloaf?
In every price range there are compromises between accurate or transparent mics and colored or warm mics. OK- $500 and under, some of my favorites- Rode NTK, a little bright, a little color. Good on blues/rock, very good on cheap guitars. B.L.U.E. Baby Bottle- a little hype going on in the midrange, very little color. Good on expensive guitars and really good singers. Better choice for a good guitar and a good singer- a pair of Studio Projects C-4's on the guitar and
CAD M-179 or Studio Projects B-1 on vocals.
On a cheap guitar and an average vocalist, AKG C2000B rocks. On a mediocre singer, just give 'em a good dynamic, say Sennheiser MD421 or a
Shure SM58. These mics are less sensitive, and will pick up less breath noise. They are forgiving.
Got a piercing soprano? Try Oktava MK319. The Oktava MC012's are small diaphragm mics that are great on cheap to midrange guitars. For guitars or vox, mics are like shoes. Cheap ones that fit are better than expensive ones that don't. Good cheap compromise? I like
Audiotechnica AT4033. My personal favorite compromise mic is AKG C414B-ULS, just out of the stated price range. You have to match the mic or mics to the source, which is why you get so many answers when you ask that question. Not all guitars or all singers were created equal.-Richie