I like Devon-Aire Versailles breeches for summer. They are light-weight & pretty sturdy. Sometimes you can find them in fun colors–I have had a purple pair, some different shades of green, burgundy; I have even gotten the plain khaki & dyed them myself with RIT. Easy! Very comfy for trail riding, schooling, & usually in the $40 price range. Unfortunately, SP doesn’t sell them. 🙁
I do like the SP Pipers, but they are low-waisted which I am not a fan of. Just not comfortable for me.