If you want an affordable replacement or backup folding tire to take on longer rides, Jenson USA has the Schwalbe One folder in 700x23 for $15 (I just ordered a pair) and 700x28 for $20 each. Not the Pro, but good tires for the money.

FWIW, both of my Vittoria Zaffiros got cut like that, without punctures, within the first 100 miles on our terrible rural roads. I watch 'em carefully. Both are fine 400 miles later.

Usually I use Shoe Goo to fill in cuts like that on my hybrid tires -- usually it lasts for weeks or months. But it didn't work for longer than one or two rides with the Vittorias. Not enough tread material for the adhesive to hang on for long. I just use the goo to fill the cuts so gravel doesn't get trapped inside and burrow into the tube. I don't expect the adhesive to actually repair the cut.