Here's the deal. You can buy a suit for $100, for $600, for $1500, or for eleventy-billion dollars.
If you're in the <$400 range, go to Men's Warehouse and talk to those guys. They'll help you out, answer your questions, and lead you in the correct direction.
If you're looking for a $500-$2000, go to Nordstroms. They'll help you out, answer your questions, and lead you in the correct direction.
When I was in junior high or high school, I got an off-the-rack, ill-fitting suits for like $120 at the base exchange, and I wore that until about junior year of undergrad. After that, I went to Nordstroms, bought off the rack and had them tailor it to me (it took about two go-arounds). After that, I had something tailor made for me while overseas. I'm really wide in the shoulders and chest, so any suit off the rack is going to need to be seriously altered to fit me.
I'm an R&D engineer. My of my customer meetings are specifically "no ties allowed" (as dictated by the customer). I wear suits like once or twice a year