6.9 gb ram a ma'am will be best but because it's binary and multiplier of 2, 8 gb ram bam thank you ma'am will have more room for os and multiple apps running at the same time.
if it is refurbished, they must declare.
Ebay sides seller, if it is not as described, you can get refund.
Of course, you reminded me that Amazon is even stricter, some are fulfilled directly by amazon. You can refer to these Amazon listings...... https://www.amazon.com/dp/B06X9PHY9Y - Acer 15in Touchscreen, i5-6200U Processor, 8GB, 256 SSD https://www.amazon.com/dp/B075RSR8QP - HP 15in Touchscreen, i5-7200U Processor, 8GB, 128 SSD
If you don't play games on your laptop. You use it to watch videos and work on some websites at the same time.
There is no option to upgrade the RAM to 8 GB at a later stage, but I wonder if 4 GB is good enough because the 8 GB will cost another $300, which is 20% of the price of the laptop.