If I'm going to wear the watch frequently, I get it regulated after the first month or two. My watch maker charges 30-40 bucks depending on the watch, but totally worth it. The comments about isochronism (consistency independent of position and temperature) are true though. Some movements just vary too much to be worth regulating tighter than 5-10s per day. Also, if your watch has a free sprung movement it's going to cost more to regulate, but it's likely to be very accurate.