No reason to buy a CD -> Amazon most likely has the single that you want.
First single that I ever bought was
Little Darlin' by the Diamonds in 1957...on a 45...88¢. Of course, it wasn't a "single" it was a "dual"...but, I don't remember what was on the other side
88¢ in 1957 is ≈ $10.00 today; so, 99¢/song at Amazon doesn't sound too bad. And, like that 45 rpm record, you can play it on anything that can play it