How do I turn off the end of support banner in office 2010 permanently? (Office 2010, Windows)

Why do you think you can trust online "reviews"? 

I was referring to the Kinguin reviews, not Plaza. If you didn't read those reviews, the link again is:

https://www.kinguin.net/category/59858/ms-office-2019-home-and-student-retail-key

They all seem to be saying that phone activation works. I'm sure you have your reasons for being skeptical of all online reviews. However, for what it is worth, Tom's Hardware spoke with Kinguin directly and reports:

“Only the original developer or publisher of a digital product can generate keys, so all of the Office 2019 keys come from this source. From there, either a seller buys them directly from the publisher or from the wholesaler, who also got them directly from a publisher, and sells them on Kinguin for a fair market price,” Michał Puczyński, PR Manager at Kinguin, told Tom’s Hardware.

Puczyński admitted there are “a few bad apples” in its marketplace but said this is inevitable since there are “tens of thousands of Office 2019 keys sold by thousands of sellers on Kinguin.” However, he claimed that only one out of 700 postings aren’t legitimate, and an even smaller percentage of shoppers actually get scammed.

“Our fraud prevention team manages to stop nearly 100% of these attempts before they take place. When a scammer is detected through our custom fraud technology, that person is banned for a lifetime from selling on Kinguin,” Puczyński explained.

Kinguin also offers a $5.69 “Buyer Protection, ”which guarantees you a refund if you get a bum key.” However, even if you don't buy this protection, Kinguin is willing to work with you for a potential refund if your key doesn’t work.

Kinguin's price currently is $34.78 and they take PayPal, so you don't have to give out any credit card info.

I stand corrected, thank you.

Office 2019 cannot be transfer to another computer. 

That is not correct. Office 2019 can be transferred to new computers. It may not be simple, requiring a phone activation, but it can be done.

.

I would not pay $149 times 3, ~$450 plus tax, for Office 2019.  Besides the initial outlay there is the risk that one of your computers could go on the blink.  Office 2019 cannot be transfer to another computer.  Have you considered LibreOffice?  It is free and many like it.  It might be worth checking.

Why do you think you can trust online "reviews"?

.

I looked at the Plaza site. The Home and Student page is very good. Just a couple of grammatical errors that can be written off to ESL. No apparent factual errors, which are the usual clue of scams.

.

The one thing I could not find on the site was any explanation of how they can sell so cheap. The only "legitimate" way I can think of is buying stock from bankrupt companies. The only other way I can think of "it fell off the back of the truck" (aka stolen goods).

How can they sell any legitimate Office 2019 license for $30, or even the "original" $90 price.   I could maybe believe $30 for Office 2010 because it was a "going out of business" (end of life) "sale", but not for 2019.

.

It's a balancing act. $30 is roughly 1/5 the retail price of H&S. 2019 has a little less than 5 years to EOL, so if you can get 1 year of use before MS blocks it you got your money worth, any extra time is "bonus".  Maybe you get lucky and you get to use it to 2019 EOL ... Maybe you don't.  Can you afford to gamble the money?  For me that is roughly 3 weeks of lottery tickets. Or roughly equivalent to a case of beer, or 4 or 5 packs of cigarettes ...

.

But, at this price, even though they say Home and Student, you may be "pleasantly surprised" they "accidentally" gave you Pro Plus ... a variation on 'bait and switch' advertising.