Do not see four inch adjustables around here that don't have a golden price attached. Picked up this PROTO at an antique shop, above it is a six inch Williams, Then 2 of the Lobster brand I have had 40 years.
For what it's worth, there are at least two different shapes of the fixed jaw. The one you show that looks like a Crescent wrench and another that has a more "pointed" fixed jaw, kind of like the Lobster wrench with the red streak on it.
I'll try to get some pictures of the two.
Mike