So, let's try this to get this back on track and positive.

Buyers- For gosh sakes, ask about rust issues. Insist on a detailed pic if you see a hint of the stuff before you purchase.

Sellers- If there is a structural issue, such as a dent or ding, include a note and a pic. If there is any rust, especially rust like this, take the time to get a really good pic and description for the buyer.

Example:

Whatwolf- If you had seen a really good pic of the rusted bb shell before you purchased this frameset, would your same decision to purchase occur? Would you have at the very least asked deeper questions from the seller?