Owned numerous pairs or Kevlar riding jeans plus riding pants, here's my brain dump on the subject.....
Scorpion Covert Pro Jeans
seem to get great ratings from multiple sources and are much cheaper.
I would avoid Sliders from Competition Accessories - the fit is terrible unless you are deformed
I like the Drag'in Jeans Kevlar long underwear, you can wear under any pants but the armor does not stick to them - Draggin Liners Review - webBikeWorld
- only issue is they are hot on hot summer days but warmer than just jeans when it is cooler.
Brosh Kevlar motorcycle cargo pants
are cheap and fit really, really well, available on EBay and Amazon plus directly. I would rate them a "two wheels recommended best buy" at ~$100US including shipping from Israel where they are made. Very cool in hot weather. Recommend going up one increment in waist size when ordering - if you take a 34, order a 36, as they sit higher on the waist than jeans.
Unlike riding pants, jeans wear out due to the frequent washing they receive. The washer and dryer seem to be very hard on these IME.
IMO Kevlar riding jeans or cargo pants are a nice supplement on bright warm sunny days, to good textile or leather riding pants, not a complete replacement for them. They don't for instance work in the cool weather or rain. I prefer my Olympia Motoquest pants on dedicated rides but jeans for commuting.
Another option is good quality knee pads such as those from Icon or Alpine stars to wear under regular street pants.