Male tarantulas generally live for about a year. Some may live longer and some will not last the year. It is variable as to how long they live and how long they are viable for mating. I cannot guarantee the viability of any male spider, I always state the month in which the spider matured. It is best to attempt mating with a younger male but it may well be worth trying with an older specimen too!
You may notice the price of the mature males going down as the months pass by!