On-Site Post Office Check & Mailing

Please head to any convenient post office in your area and have a quick chat with the counter clerk. I need three clear answers: 1. Do they have regular postage stamps for sale right now? 2. Do they stock postcards on-site? 3... (Budget: $10 - $30 USD, Jobs: Customer Service, Flyer Design, Graphic Design, Logo Design, Photography, Photoshop)