The September Model Railroader contained 372 Retailers in the Directory section of whic there were 88 that specifically included "Z scale" or about 24%. 21 said "all scales/gauges" but we know what that means.
One of the Hobby shops favorite slogans is we carry everything from A to Z. Which means we can order your z scale stuff.
And we all know that Walther's has just about the worst prices for Z out there. When I first began in Z scale not quite 5 years ago, I went to order some PECO flex track from my Local Hobby Shop (that actually does carry some Z scale). I unfortunately got the "Grumpy old HOer" clerk (even some of the other clerks call him that) and he didn't believe me that Peco even made Z scale track. I had to go get the Walthers catalog and look up the part number for him. Since then I only deal with another clerk that is a Nn3er when it comes to stuff like this. I have noticed lately that their Z scale stock is improving as Z becomes more popular. ;-) Randy