I'm going to change my own oil $28.17 for 4.5 qts of Mobil 1 0W20 plus the cost of the filter, which was $4.50. I bought 4 yesterday from the dealer for $18. The total cost for me will be $32.67. Walmart has the oil filter wrench 65/57 mm X 14 for around $2. Their oil is $6.27 a quart for the 0W20 Mobil 1. I am stomping at the bit to do my first oil change, which is 1,450 miles away.
$14 plus oil at Northwest Toyota in Chicago. New tires gives me "free" rotations. Or Midas does oil and rotation for $20.
When I bought my 2007 Prius(June of 2007), I bought a small floor jack with 2 jack stands from Sears on sale for about $30. I then for the next 2 years when I changed my oil I would also rotate my tires. It took less than 30 minutes to do. You can do a search and find where people have used a floor jack and used one central point on the side of the vehicle and jacked it up. I did that and then used the jack stands to make sure it stayed up. That is what I plan on doing with my 2010, I have not looked yet but it should work about the same. No need to pay a dealer to do something so easy to do your self IMO.