Is a sheet of old stamps worth more to a collector than the sum of the individual stamps?

Let’s say you have an intact sheet of 100 first class 5-cent George Washington stamps from 1968. Should you keep the sheet together or separate them into singles or smaller blocks if you want to sell them?

That’s not just a matter of value either, right? You can find collectors on, say, eBay that would buy smaller quantities for pretty good money. But where would you find somebody who would pay x thousands for the whole sheet?