The parts are not aftermarket, the are OEM (when u go to a parts store with part # and brand specific parts u r looking for, they generally r not in stock and r ordered directly from the manufacture or places like Worldpac that warehouse OEM parts), the point of the return mention was if it was a crap part u can return said before ever installing.... OEM doesn't not mean u have to go to the dealership. How u want to spend ur money is not my business, but just because someone spends x2 x3 x4 for the same part doesn't make it more OEM then the parts that come directly from the same manufacture but simply have a Toyota sticker on the packaging. Doing a little research can save peeps a lot of $$$$. Denso and Aisin don't have bins of "Toyota quality parts only" they grab and send whats on the shelf when orders come in.... they build quality parts to start with, this is why Toyota uses them as a parts supplier.

Buy what u want from where u want, I use the stealership all the time for convenience and because the parts in stock when I cant wait...

There is a difference between aftermarket and OEM supplier, when Toyota designs a vehicle or re-designed the 3rd gen 4R, Toyota engineered/designed the new parts needed if they could not reuse the parts from the previous Generation that had been proven to work through previous R&D, they went to 1 or more manufactures and had components built to Toyota specs in partnership with supplier and put them through tests to insure they would meet the manufactures requirements and QC, aftermarket companies built there parts using data from the original supplier and have no R&D, Toyota and the OE supplier has years of R&D and is using the best combination of metals, rubber, grease, hardware ect, for application. And what any non oem supplier is using is anyone's best guess. Now the problem exists where we don't know if we are buying repackaged Aisin, denso, NOK, Koyo, Sumitomo, mitsuboshi, Bando from who knows where unless we go to a Toyota dealer or known good vendor. I know I've had this in my cart for awhile but worried it might not be as advertised. I use my local dealer usually, got burnt a few times doing things twice going aftermarket, buy once cry once.

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ok, i appreciate the research and development and manufacturing and parts specing/sourcing that goes into OEM parts. BUT WHY IN THE HELL do Toyota parts cost so much more than aftermarket parts??? Just priced parts for a tune-up on my 2000 4runner 3.4 V6 (plugs, wires, coil packs), and figured may as well replace the injectors while i was at it, as I would have to make the same tear-down for injector replacement that has to be done for a tune-up (appears the original injectors were still in service ay 240K miles, bless 'em). But $560 !!!???
I did some research/checking (semi-retired attorney, computer research has made me a lot of money) and found NEW injectors, spec dual electro plugs, 3 coil packs and wires, and the throttle body and plenum gaskets (necessary replacements when you take the fuel injection system apart to get to the coil packs and plugs), all for less than $200 delivered to my door, on Ebay.
Yes, I would rather buy from the dealer. Yes, I would love to have that close relationship with people I would like to depend on to maintain my daily transportation. Yes. I have bought a few beers for dealer service managers and dealer techs in my past years. And I have learned, and I am sure the reader knows, to build a $30K car from the parts sourced from the dealership parts department would cost $100K. A real pity, and an open secret.
I cut my teeth wrenching on '60s and '70s muscle and "fun" cars. After watching Timmy the Tool Man and a few other videos, I see nothing to prevent me from tuning up this little fuel-injected V6, but dealer parts prices are OUTRAGEOUS. I understand "Toyota reliability" that is engineered into, and expected from, the branded parts. But when shop managers tell me they regularly use Ebay parts to cut overhead, why should I pay dealer service prices for something I can do myself, with the same Ebay parts??

Sometime in the last 20 years or so, Toyota USA decided to start gouging on parts. Not all parts, but many/most. And...sometimes, the price goes way up, and then a few years later it goes down.
You just gotta know that $150 is too much to pay for a $40 brake hose.
I surmise that their market research has told them that so few people perform any of their car's own maintenance/service these days, the consciousness of parts prices is more or less gone from their customers minds.

Everything has gotten more expensive, so I guess that includes parts.

That said, the laundry list of parts on my truck which are still original and still work great is long, very long. So after 21 years, I don't care, I'll pay for the Original part.

On the other hand, I have german cars whose part prices are truly outrageous... and they barely last 40k-90k miles.

For any safety/critical or tough part to replace, I'd get the Original Toy. Otherwise, I'm open to aftermarket (though that's really not very many, maybe just an air filter at this point, unless it's an improvement like new lift kits, etc.).

There are a lot of denso parts that are priced fairly and are good quality.

If they are genuine. There are so many fake parts out there. Spark plugs are a good example.

next project is the radiator and timing belt/water pump combo. I realize the critical importance of the timing belt and water pump, along with the difficulty/expense of getting to them, makes the reliability of factory parts of apparent and obvious necessity. So the $80 aftermarket timing belt kit on eBay versus the $300 factory parts set, while tuff to stomach, seems to be appropriate. Not so sure the same can be said for the radiator, when there is a hundred dollar price difference between the dealership and Advance Auto (with the latter's lifetime warranty).

Before you make a decision on the radiator, make sure you read up on the pink milkshake and are comfortable with the risk of a radiator failure, or have a plan for preventing the damage it can cause if it happens.