I read some articles saying there is now a "stamp fee" when entering Vietnam. Can anybody confirm if there is an additional fee on top of the $25 I am being quoted by he Vietnam e-visa website?

I didn't have pay anything extra on the border at Lao Cai, a few weeks ago.

If you applied for e-visa, no additional fee on top of 25 USD/ 1 month single entry visa. But if you applied for visa on arrival, stamping fee is required.