Recently at a low-end beach restaurant lunch, the first two wines we asked for were "not available". But the server subsituted a Sutter Home cab, at somewhere around $30 and asked if that would be okay. No! That stuff is $4.99 at the grocers and even a 3x markup would be $15.
Finally the server came out clutching 6 bottles that they did have and asked us to choose. Kind of funny as she had no clue what they cost, and the price varied from $20 to $50. We matched them up with the plastic menu (yes, with pictures) and made the best decision - some sort of red at about $25. Acceptable with the burgers and BLT's, but beer would have been a better choice perhaps.