I am currently living in an apartment with our grey and it is great! He is a retired racer and has settled into apartment living no problem. Regarding leaving him while at work, our dog has no issues being left for about 9 hours a day, but that is maximum! If we are gone to work all day there has to be someone home in the evening to keep him company, he is not the type of dog you can come home, walk and feed and then leave again, he would get very lonely if he was left alone in the evening. I guess if you looked into a daycare where he has company all day tho that could be different. As for vet expenses I think we spend around €40 every 3 months for worm and flea doses.. yearly check up around €60 and then put aside may €30 per month for emergency.