I pieced my armor together from different places & people so it was cost-efficient but still had the look I wanted for its intended purpose (i.e. combat fighting, jousting, theatrical, etc). Safe to say, I gave lots of medieval enthusiasts/merchants some business over the years. Make sure your armor is authentic-looking to your character (or look you want to portray) but more importantly that it serve its intended function. Heavy-guage for combat-use as opposed to light-weight aluminum for a day of renfaire theatrics. Purpose matters for armor. You can get great deals on ebay, 2nd hand or even custom finds being sold reasonably priced by previous owners for your 1st armor kit or suit. My suggestion is same.... do what works best for your wallet. However, still shop around unless you are totally committed to buying your own custom-made stuff specific to you. In that case, do it right & find a quality armourer for what you want.
I wear a combination of padding, maille, and plate armor but my intended use besides being authentic is for combat-fighting. I'll wear different armor pieces for freedom of motion but without compromising protection. Make sure your stuff is articulated & measured properly. Functional armor is ALWAYS RECOMMENDED.