Anchor Hocking 4-piece 6-oz. glass custard cup set with lids for $3.99 on Amazon

Amazon has got this 4-piece 6-oz. glass custard cup set with lids for only $3.99 (Add-On item).

• Custard cups 8 piece set (4 cups plus 4 lids); mix, bake, serve, store; four smooth finish 6 ounce cups and four odor resistant bpa-free stain resistant plastic lids with air tight seal capacity
• Cups nest into one another and glass is made in USA
• Oven-Safe up to 425F; 
• Dishwasher-Safe with lid in top rack; 
• Freezer-safe; 
• Microwave-safe with gap/vent required between lid and glass

This is an Amazon Add-On item, which means that it ships for free with a $25 minimum order if you are an Amazon Prime member (and its price of $3.99 counts towards that $25), or it ships for free with a $49 minimum order if you're not a Prime member.  You can buy multiples of this item to help get you to your $25 or $49 minimum for free shipping.  (Other Amazon Add-On item deals can be found here.)