I was browsing through JoAnn's Fabric and Crafts the other day and in a display of summer picnic/table ware found some sturdy fat straws. They are 3/8" in diameter and were 99 cents for a pkg of 12. The salesperson said they were just a temporary display item.

I don't know what bubble tea straws look like, so I don't know if they're similar, but they're definitely bigger than regular straws.

Just thought I'd share.