I hear you all on the ageism thing! I mean, I don't feel all that young any more at 30, and I have 20 years of knitting experience, but try to explain that to some of my 40-60 year-old LYS-customers. I work at a yarn store, they didn't hire me because of my pretty smile, goddamnit!
I'm in my 30's and I work in a LYS as well. There's another girl who works with me and is in her 20's. We both often get asked if we know how to knit....
I've started to respond with a huge smile on my face "Of course I do! It's a requirement for the job." And then they usually soften up a bit. Sometimes, I'll show them my current project, lately it's been fair isle and cables in baby garments and then they usually start to trust me.
I also wanted to add that I know some customers who have shopped in our store don't get along well with the owner, who was a former english teacher and can talk down to customers at times without realizing it. We all have different customers who we get along with moreso than others but we try to treat everyone equally, novice or expert and give them what they need and hope that it matches what they want as well. We're a very reasonable bunch and we often suggest cheaper substitutions if a customer balks at a pricier yarn. Sometimes, we don't have something to substitute but we sure do try to accomodate people. Plymouth Encore is our biggest seller, mostly due to the fact that we sell afghan lots of it, but we carry so many different brands to suit all price points and have a great sale bin that even I shop out of when I get the chance.
Our shop uses the sale bin to move yarns that there are only a few skeins left of in a dye lot or to get rid of yarns that haven't moved in years to make room for new yarns. We sell yarns in the sale bin at either 30% off for sweater lots of discontinued yarns or 50% off of odd skeins....and that's Rowan, Debbie Bliss, Tahki etc. The good stuff. The thing is, 50% off is cost. The sale bin is there to move yarns primarily but also to draw in customers in hopes that they might buy a full price skein or two (or even a sweater lot) on occasion. If a customer shops exclusively from the sale bin, the shop makes $0 on that customer. Please don't jump down my throat for pointing this out. I understand that some people are on limited budgets and that yarn is a luxury and that in order to get the best yarn for your dollars, sale bins are your friends. All I'm saying is that if you want to support your local, friendly LYS, buy a full price skein now and then if you can on your budget along with your sale bin purchases. If your LYS is snobby, then shop from their sale bin exclusively and cost them money in operating costs and wages to serve you.