This statement could very easily be taken as if she was saying that unless a woman can afford to buy clothes at full price, she can't be stylish.
But to be generous to her, I suspect where she was coming from was from having worked with a lot of women who loved a bargain, and bought clothes with sales goggles on. Then they ended up with a packed closet that lacked the basics, didn't work together, and had no clear style.
And yes, if she meant that it's hard to find the right basics in the right color and the right size on a clearance rack, she's right. Unless you have plenty of time to hunt and you're willing to wait to buy until you find what you need. But if you're working with a stylist and she's helping you shop, she's not going to find those items for you on a clearance rack during your shopping trip with her. So coming from her world, she's likely correct.
But outside of her world, nope. As a shopper of low-end clearance racks and thrift stores, I'd say you
can absolutely have style—if you're patient and if you
put items that cost $17 or $27 through the same set of criteria you would put
them through if they cost $127.