Would you chance a used evap canister off of ebay?

Always Risk vs. Cost.
Can you afford the under $50 risk?
If you feel you can afford the gamble, that is, absorb the possibility of it simply NOT working and being a total loss, (worst case scenario) then go for it.
If the gamble would leave you scrambling for a solution you cannot afford if it fails? Then forget gambling.

 

MSRP is $360, you can buy the part for $260 here:
VAPOR CANISTER for 2004 Toyota Prius|77740-47050

Since you are concerned about having to install a used part twice and the associated labor, it would be reasonable to buy a new part.

 

EVAP Canister is typically a low tech (no moving parts) device that gathers fuel fumes.
Smog device so I think OEM canister has an 8 year warranty.
Why do you need a replacement?

What year car?
How old is the e-bay unit?

The gamble is age and miles used on that e-bay unit.
I have not opened a Prius Evap canister, yet some other brands utilize a foam in them that breaks down over time.

If you can get history of the part, based on new vs used price...maybe I'd buy used.
Based on your reasons for needing one....maybe I'd try to repair.
For my personal time efficiency (is this a two hour project: find used, shipping time, parts verification, install, etc)... I'd buy a new one.

Your decision.

 

I also think you need a good labor estimate before you make the decision. It looks like a new part is about $200 more than used. (It looks like the new part includes a vacuum switching valve and tubing, and used parts may not.)

I personally have had very good luck buying parts like this off eBay and I would take the gamble for a 12 year old car. But I have the time to do the work myself, and it would probably be a fraction of the labor if a second replacement were needed.

Assuming you're driving with check engine light on, keep in mind you may not be alerted to a new code. That would bother me and I'd fix it sooner rather than later.

 

8yr warranty w/ a new car. This is a replacement part, well after the original new car emission warranty has expired so 1year/unlimited mileage warrant for this replacement part.

To get 8year warranty again requires new car purchase or used car purchase that still has emmission warranty remaining.

Hahaha, "How old is the eBay unit?" Is there any way to independently verify the part year, outside of what the seller says it is? Sure a part number is likely stamped on the part, but it will correspond to the entire generation 2 Prius (2004-2009) or a few model years as part numbers get supersceeded (2007-2009, actually off a 2007 but seller say 2009). Seller can say anything and usually get away with it. Joys of eBay: lies, lies, lies yeah (Thompson Twins)

 

Living here in California, when it comes to smog components, I opt to by new. I just shop around for the best price. Places like Rockauto, autozone, O'Reilly, etc. That way,if it is new, if something goes bad on it, it can be exchanged. When it comes to your car, if you are buying components to keep it running, I generally stay off ebay or craigslist. If you are buying mod stuff, then the risk is less. Just my too cents.