Most egg donation programs only take donors who have successfully been pregnant and given birth to a healthy child. There are a LOT of genetic tests done (more than in sperm donation) and the procedure is a minor surgical procedure, which can take up to a week to recover from, not to mention several months of several times daily hormone injections. the hormones are done for months before the "Harvest" to get as many eggs as possible.
You also CANNOT have sex during the entire thing, the whole Fertility Treatment, because you could get pregnant with quads or quints etc, because the medication they give you causes you to ripen up to 12 eggs at one time. Also, if you do get pregnant, they often refuse to pay you, and you may end up having to pay for the expensive hormones yourself, because NOT having sex during the treatment, leading up to Harvest is part of the Contract you sign.
You also have to contract not to drink any alcohol, no meds for any reason, no tobacco, consent to lots of genetic testing, suffer the mood swings of intense ovulation drugs, in addition to ANYTHING the perspective clinic or parents request. I've heard of women being told they can't eat peanut butter or gluten during the procedure to "prevent allergies in the baby" (which I think is bullshit, but the people PAYING for the eggs get to ask for what they want.) And it isn't just jerking off, like guys do, it's a 1 to 3 month commitment, where your body belongs completely to the clinic and the prospective parents.
I would not do this. Just the PITA aspect alone is bad enough, but someone else raising my kids would bother me. I'm a picky Mama, I adore my kids, and am picky about the occasional baby sitter, when my kids were little. Someone with my egg and eventually my child? Not for me.
But, every one's mileage will vary.