Uline has a 50 pack of surgical masks for $29 + shipping (approx $15 for me). Max 6 packs per customer and yes they appear to be made in China.
Listed as ASTM Level 2 (98% particulate filtration) and FDA 510(k) reviewed/cleared? as Class 2 devices:
Product (was only able to see this using a desktop browser):
FDA 510(k) Pre-Market Notification:
FDA 510(k) Summary, Testing, Review:
Getting a better seal with surgical masks: