That looks like just rods. You also need a stroker crank, pistons, rings, and a good machine shop to balance it all to even get started on a stroker. $250 is not a bad price for a set of lightly used forged eagle rods though. Look at them first and make sure there is no scoring in the main journal area showing signs of a spun bearing. Also budget for new bolts.
*** Always remember that with used rotating assembly parts you won't know if they are good or not for sure until everything is put together and measured. There is potential for big savings but always a risk of buying junk. Just keep that in mind.