Do you save money using cheaper paint?
NO, it will cost you more in labor because it will take more coats for an even coverage.
Does cheaper paint cost less to maintain?
NO, it usually can not be wiped down without smearing or removing the finish. It usually does not have mildewcides, or stabilizing agents to maintain a fresh and clean look. It also usually fades or darkens quickly causing you to repaint sooner.
Is there paint with no or low odor?
YES, Sherwin Williams makes my favorite paint called Harmony. It has zero VOC’s (Volatile Organic Compounds) which is what you smell in most paints and is not good for our atmosphere. Oil based paints are the worst offenders and I refuse to use them for this and many other reasons. Other paints can “out-gas” these for up to 2 years!
In summary, using the best paints will save you money! Not to mention, it will look the best too! Cheers!