I can't really see any logical reason for the salesperson to redirect the a shopper's attention to a less expensive bag except a judgement that the shopper can't afford it. An exclusive shop where they actively try to steer all their customers to less expensive items? I don't think so.
It's a sales strategy - and it works for some people.
You: Can I see that expensive [purse/car/necklace/whatever]?
Salesperson: Oh, no, that's only for special
customers! We don't want just anyone buying it, you know! Wouldn't you rather see something . . . less exclusive?
You: Hey, I'm special! I'm exclusive! Here's my eleventy-billion dollars; I must have that purse/car/necklace/whatever!
Lots of "boutique" clothing stores do this - they don't sell anything in plus sizes (so "ugly people" won't wear their clothes), they harass shoppers who don't fit their target demographic (young/pretty/thin/rich), they purposely price things much higher than their operating costs would dictate, etc. And by doing this, they give their clothes an extra cachet. There is a segment of the population who will buy them because they want that identity - if only young/pretty/thin/rich people wear Brand X, then if you wear Brand X, people will know you're one of the cool kids! You're young enough/pretty enough/thin enough/rich enough to hang with the exclusive crowd!
It's annoying as heck when you're on the outside looking in, of course - how dare they say I'm too old/plain/overweight/poor to represent their brand? - but those brands don't particularly care about annoying me