When we restarted in raising cattle, we bought some open cows, bred cows and a few heifers. Recently we only have the heifers left, which dropped their first calf last spring. The cows were older ones 5- 9 yrs, still had good life and were healthy. The problem I had they would not breed back, we A.I. all of our herd. No bull on premise. The cows that were purchased were not registered (we bought them to give us market animals) but the heifers were. It all depends on your goals you want to achieve in your herd, we where looking for certain gentics and with the gentics we wanted, the cows where proven and the cost was up there. So we decided to go with the heifers and get a little better price and get them at a younger age so our kids could get to able to handle them, and not to afraid of the larger animals. Again, my opion is what do you want to achieve in your herd. Good luck and God Bless.