Oil Change - Toyota Dealership Suggested?

I would buy the oil I wanted (Mobile1 0W-20 at Walmart for me) and the OEM filter (over the web in your case), and take them to a quick lube place where you can watch through a window or from just outside the change bay. If I were planning a trip near a toyota dealer, I'd likely use the dealer, and specify the Toyota 0W-20 oil.

I do my own, and will continue to do so. The only things unusual in changing prius oil are: 1) the filter is a cartridge that drops into a plastic housing, 2) with the filter cartridge comes a new o-ring to go on the plastic housing thread area for a good seal, 3) you have to remove and reinstall 4 plastic push pins to allow the plastic undercover access panel to open for access to the drain plug and filter, 4) you really want 0W20 instead of the usual 5W30 dino oil, and 5) the undercover access panel tends to break off due to over flexing (it is a poor design).

It is well within the ability of the oil change places, though they will likely destroy your undercover access panel with time. Make sure the access panel is not hanging down after each change, whether by quick lube or by dealer.

 

We have about the same situation, I live in a very rural area, 100 miles from the nearest Toyota dealer.
My thoughts, My 2010 Prius only need the oil changed at 10,000 miles (still looks almost new at those miles)
Once per year I make an appointment with my dealer to change the 0-20 synthetic oil, check and fill all the coolant and other Toyota only fluids, rotate tires and generally check everything that may need attention.
Has been costing me around $50-$60 per year(actually about 14 months with my 9000 per year)

In my opinion, it is good service by people who have all the correct stuff on hand and know how to do it.
I feel it is reasonable priced peace of mind.