No matter how much you leave there is a long, hot - probably dry - summer still ahead. If you leave 60 pounds of honey that equals about $300 retail in my neck of the woods.
So what if they eat all of it during dearth between now and fall? Then you have to spend another $30 to get them back up to weight for winter - leaving you $30 in the hole.
Whereas if you take just half of it now and sell it for $150 then even if you have to replace it now with $45 worth of sugar ($15 for the 30 lb you rob, and $30 to get them up to 60 lb in the fall) you are still in the black by $105. Not counting other expenses of course.
If you take $150-200 worth of honey, eventually you will have a vested financial interest in keeping your bees healthy - not just a casual (hobby type) one.
One way is a hobby that costs money and the other is a hobby that makes a bit of money - and a lot more motivation to keep your bees fed and healthy year after year. And a lot different point of view for your wife if you decide you want 25 hives.
So in theory, making a profit is in the long term interest of the bees - in theory.
Just a thought.