I get from the poll that 77% of the members have 10 hives or less - at least those polled. I think 10 is a fair number before jumping up the big notch - not that 8 or 9 hives is easy either.
Sometimes I'm really glad 4 hives maxes me out, where three is a nice looking yard ornimate. My neighbores know of my bees, if they move I wouldn't mind FIRST teaching the new neighbor the benfits of bee and then if they SWORE they had allergies, I'm move the bees to the oppisite side of the house with little sun loss.
Keep thinking ahead and this is a pretty great hobby, if you have good weather too, think of yourself as fortunate. It is VERY DRY MANY PLACES and honey stores are down, even pollen has been effected. Might be a tough year, get them as much room as they need to store honey, it may come late this year.