Probably not. DVDs and the like offer what you might think of as a "volume discount." In other words, you can buy the whole 45 minutes and pay, say, $25. Or you can buy only the particular 5 or 10 minutes that most interest you and pay $5-$10. It's a higher price per minute, for exactly what you want, and a lower total price.
Now, I suppose some sites might offer some kind of custom discount on large purchases. In other words they might let you pay, say, $30-$35 for 45 minutes worth of short clips that you choose to suit yourself. That's still more than the $25 that you're paying for a 45 minute DVD, but it's all just what you want so you should expect to pay a small premium for it.