I've had the same set of folding steel sawhorses since the mid 1990's. They're sturdy and fold up small, but it's a pain to adjust their height. Not so with these folding sawhorses from ToughBuilt – their legs can be lengthened by pulling them out and shortened by pressing a button and sliding them in. This means you can quickly and easily adjust the height of the horses so they're level on uneven ground or to suit the work you are doing.
I haven't used them myself but saw them demonstrated a couple of months back at the JLC LIVE tradeshow. According to the manufacturer they hold 1,100 pounds apiece and go for about $35 each.
I have a pair that the legs do not adjust. They have been replaced once and are not set up well to put sacrifice wood on top. My stabilas have never had problem with shaking apart. The big seller to me was the space that they take. Too many moving parts mean failure. The side clips to hold up sheet good work but not well.