Replacement for MacBook Pro

REVISED. Homebound because of oxygen used 24/7 for emphysema and and so far successful surgeries on both eyes . So far my computer is my window to the outside world. I use it 9 or 10 hours a day. My MacBook has a cracked system board. The cost of a "new - 2012 system board is around $600, if they can find one. And the cost of a refurbished MacBook Pro is around $650. Any overage will go to the animal shelter where I got my dog. Thank you!