I think it all depends on what you have and want to spend. I have about 15K into my project on the s10 frame. It drives great. I picked up a running s10 for $1300 and sold $500 worth of parts from it. I also sold the old frame for $400. So for about $400 I did have an s10 frame. I did spend a lot of time doing custom fabrication though. I think if I was to do it again in the interest of time I would have probably tried a custom front end and 4 link in the rear. But again I had an original frame that didn't seem like it was in that bad of shape. I would have spent some extra time on boxing it in though. As stated if you are going to use every piece then obviously the s10 is the cheaper way to go. I didnt use the engine or transmission, steering column, steering wheel, pedals so I spent more money. I also wasted about $500 on buying poor quality parts or switching to something else that seemed to work better. I also paid someone to do my wiring ($850) and he really didn't do a great job. Lots of stuff wrong. He wired my alternator wrong and burnt it up ($150). Lots of wires wrong. I probably am not much help.
I do like the fact that I can go to any parts store and they have all of the parts I need in stock or at the local warehouse.