Extracting eggs is a MUCH more intensive procedure than sperm donation. Basically, a woman's body is programmed to only release one egg per month. So the woman has to inject herself with hormones every day for I a week (or 2?) to force the body to make multiple eggs mature at the same time. Then, as the time for donation nears, the doctor repeatedly checks the ovaries (using a vaginal ultrasound device) to see if the eggs are ready. Then, the doctor inserts another device to extract the eggs.
So it's a lot more annoying than sitting in a room with a cup and a porno mag. Plus, there's the risk of
Ovarian Hyperstimulation from taking all the hormones.