Do banners still work ? I was reading that there is such a thing as banner blindness.

Banner blindness depends partly on the target audience, and partly on your use of banners on your site. If you use a lot of banners (like many people who have Internet Marketing blogs do), your visitors are more likely to ignore all of them, than if you have just one or two well placed banners.

Of course, Internet Marketers are notoriously banner blind, so that audience isn’t a good fit for banners.

As you suggest – a price, location or other “sieve” will often sort out visitors that are unlikely to actually convert.