I wouldn't put $400 into a nearly 8 year old laptop. Even with those upgrades a 2010 Macbook is going to be well behind a modern one in performance, not to mention the screens are so much better on the new ones and that's something you can't upgrade.
I was actually faced with pretty much the exact same decision earlier this year as I had a 2010 Macbook that was having some issues. I opted to go with a refurbished one from the 2015/2016 models (the ones prior to the current ones). The performance and screen are fairly similar to the newest generation and it's so much more convenient having USB, thunderbolt, HDMI, and a card reader onboard compared to only a few USB-C ports and nothing else. The one I got is $1099 when it's available, but they usually get snapped up pretty quickly:
https://www.apple.com/shop/product/F...retina-display
Even if want the newest generation I'd consider refurbished; they're essentially identical to brand new ones and carry the exact same warranty. The one you're looking at goes for $1609 from there:
https://www.apple.com/shop/product/G...lay-Space-Gray