That's not very old. $25 is less than it's worth.
Also if you buy a not-kindle (some better) you can use it to buy Amazon ebooks and Download for USB transfer.
$25 isn't worth the risk of losing some ebooks either. Admittedly a 7th Gen Basic is poor compared to a 7th gen PW (Maybe PW3?)>
See
https://www.amazon.com/gp/help/custo...MQC26VQQMM8XSW
The 3rd Gen and later let you read KF8/AZW3 ebooks. A 300 dpi (if it's not) or bigger than 6" is good, but a PW3 is just as good to read ebooks as a new 6" Kindle.
Here $25 is only the price of 2 to 4 non-discount paper books.