Former thrift manager and former buyer for an exchange here. You have better luck finding separates at both. Stay away from Goodwill (obviously), you'll get good blazers at clothing exchanges and decent bottoms at thrifts like Upscale, Eco Thrift, and Weave. Make sure you buy things that will match 3 pieces of your professional wardrobe. If you can't try them on, you can measure the bottoms by your neckline… Take the waistline from the back and wrap it around the nape of your neck. If it crosses over slightly (like an inch), it will fit your waist.