Advice on buying lens

For my Z30 + FTZII

§Last month I got from Amazon Ue Warehouse a Nikon AF-P 70-300 5.6E for <650€>
A wonderful lens so far, but a little short for what I hope to be able to do.

§To have more reach I'm looking for a Sigma 150-600 C (f/5-6.3 DG OS HSM)
So far I've found:

• a 5 year old "seldom used" for <650€> to be sent on "return if different" guaranty
• a "mint" still in his plastic envelope for <850€> - with a three hours ride I can go to the seller, check it, pay, and collect if I like what I see.

I never bought Used lenses from private.

What do you suggest as precautions??

( I'm quite afraid, to be frank - this lens new is over 1.100€)

• a 3hours drive is not appealing and costs around 120€
• the 650€ seller has a fantastic reputation

and a 320€ difference is quite a lot

As long as the return policy is good, no harm in saving some money.

Thanks.
Yes, it's true.... BUT... you don't know if the return policy it's good .... until you try to return it. 👀

The second point is:
Will a 5-year-old Sigma need a firmware update to work with the FTZ ?
🤷‍♂️

Tom Hogan's site refers to Sigma as "working"
1)

*I was asking in the hope that somebody has direct experience. * (various results from Web search )

Well, I guess that's true. If they have a good reputation as you stated, that should be a sign that they have done right in the past. Since none of us know the vendors you are referencing, I am not sure what more there is to say on that.

Regarding the lens itself? Do you know that it is 5 years old? I bought one of these new last year and it works great, no updates needed, but if it is truly 5 years old, that's about the time the Zs were released. I would think that if it does not have the update yet, Sigma could do it for you. Or you can get the dock if that is not practical. I know a number of people on DPR have been using these lenses on their Zs, I just don't know how old their lenses are.

I asked the seller and that was his answer "4/5 years, need to check the sale receipt".

As for the reputation he did a lot of buying and selling on the "TuttoSubito" Italian system - the guaranty and reputation are offered by the TuttoSubito.
(Subito for used things it's like a Craig list in USA)
- and everybody says of him "He is an expert" then "kind" ... "got fine item" - believe it or not, 50 reputations top stars, that's it.

He found the receipt >>> Dec 2015 !!! 8 years old !!!
It was his own lens... and he didn't use it much, it was bought for BIF.

Hahaha... we all do mistakes more than often 💱
( he justified himself as ...being a Hasselblad studio photographer )

I have a Sigma 35mm/f1.4 Art from December 2013. In fact that is the only non-Nikkor F-mount lens I own. That lens works fine with the FTZ on my Z6 when I bought that in 2018, without any lens firmware upgrade. Therefore, there is a decent chance that a 2015 Sigma may work just fine.

Really thanks.

That's what I posted this thread for.

Good (or bad) feedback on a reality I don't know at all.