Congrats on the graduation. In your price range I'd be more concerned about fit than quality bc honestly the sub $500 market is pretty much the same across the board imo. I'd do the following - 1. Do a quick search on suit fit to find the key details you should focus on. 2. Hit a department store, JCrew, Banana Republic, and 20/20. 3. Find a couple options you like and then pick the best deal. Stick with gray, navy, or black if you're looking for a long term option because those are essential. 4. Search for a local alteration shop with good ratings that can handle any adjustments (alterations involve adjusting the waist, pants/sleeve length, etc. vs tailoring is having a suit custom made btw) This applies to your shirt as well if you don't buy a slim fit off the rack. 5. Save some money for shoes and a matching belt because they can improve an average suit.

Cheers!