Think in terms of:1) how many rounds a year. 2) how many years will I live. Multiply the first number times the second, then round up to he next 1000. At this point double it(for tradeing material) or triple it to cover your sons future needs. Primers are sold in cases of 5000. They will not be going down in price! I have shot some of my own primers that were 25 years old and primers that were in boxes of reloading stuff I aquired that were 35 or 40 years old. The most important part is to keep them dry and not too hot if possible (don't store them in the attic), but I have some that have been in the top of the barn for 15 to 20 years and they work fine. 5 or so years ago I lost my job and sold several cases to a LGS at his cost, and got $800 which paid for our heat that winter. I started building back up my reserves this spring and lost my job again. This time I sold my 330 pound lead reserve, so these stockpiles are handy to have in hard times. Ivan
P.S. I'm 50-60 thousand primers short of my reserve target.