I'm no expert, but I think what you saw was the model 27. The "highway patrolman" was the model 28, which was a budget variation of the 27. To my knowledge, the model 28 was not offered in 3.5 inch barrel length.
Given that the gun you saw was in a wooden case, I'd guess it was a model 27. This was the cadillac of 357s.
Either that or what you saw was a four inch model 28 that someone put in a presentation case.
If a four inch 28, $500 is a bit expensive.
If truly a 3.5 inch mint 27 with presentation case, I'd be waiting on the step of the gunshop when it opens on Monday.