I have 3...a yorkie and 2 chi's
2 females and 1 male
Its not expensive at all! the only time it cost is when you have to take them to be spade/neutered. Of coruse you have to be ready for emergencies.
Once they're all housebroken it'll be easier..I know it was for me
It's really cute they play together..sleep together..eat together..go outside together..tease each other..chase everything together..you get the idea
oh and I forgot to mention the annual vaccinations for all 4