Having read the other posts, I guess I will jump in here. When I compare the costs of sanding and a few coats of paint and poly, that just isn't that far from new vinyl and you don't have the paint problems coming up in a few years.
Compromise with your landlord, you pay half and he take the other half off of rent. It will be a favor to both of you to get a new floor for half price each and also avoid you looking for a new house and him finding a tenant who might be a lot worse to deal with. Good luck.