It really depends. If the strip is really nice or rare it will sell at a premium but if you can cut it down and yield a high grade card for slabbing that might be the most efficient way to make money. I cut up a W565 sheet--they aren't rare--to get at a card and was very happy with the result:
I sold off the balance of the sheet and made money on the deal.
It can be a little nutty when the registry comes into play. I had one fellow pay me a premium to cut up a really rare strip I was selling rather than take delivery on the uncut strip because he wanted two cards from the strip for his registry set. I cut the strip, got paid full price for the entire strip
and kept 8 of the ten cards, including the fighter I actually collect.