Hi Shinebone, W&S guns are very good quality guns in almost all aspects. I have never heard of a bad one. The fact that W&S made actions for several well known, famous makers, both in London and Birmingham speaks volumns for the quality of work they did.
As to the A&F guns, they are just as good as all the other W&S guns. It is very hard to go wrong with one. I have a Model 500, Grade 2 in 16ga. It is a wonderful upland gun. It weighs in at 5-14 and handles like a dream.
The one gun W&S did make that I'd avoid is the "Texan". This gun was made for the American market with PG, BTFE and get this.....an engraving of a Long Horn Steer on the action plate. Not that the quality is bad, just the looks of the thing.
Price range that you mentioned is about right. As in all English guns, some have been rode hard and put away wet and others as pure gems. Judge the gun comes into play here. Judge each on on it's own merits.
If you get a good condition W&S you won't be disappointed. They are very good guns!!!
Good luck and all the best!
Greg