Welp it depends on your life. Do you have enough money to feed the critters, time to love on them & spend with them, money for vet bills (or a credit card sitting empty waiting for illness/old age of cats)?
We all know ya room in your heart. That's the easy part. See I went to the Humane Society once, too. Just to take a gander. Wound up going through a background check and fallin in love with a little scrawny orange tabby. He was my fourth adoption! And last year, I took in two more!
I wouldn't have it any other way. And I have a kid to raise, a house that needs work, etc. But I tell ya if I could, I'd adopt more pets. I just know my limit.
So what's your limit? If you are considering adopting the lil guy, I'd say, you haven't hit the limit yet, and you should go for it. Remember to quarantine him in his own special room before letting him meet the rest of your clan, or who knows he might be like my Hammie and just bolt forth and put his paw out for introductions.
Like others said be prepared for vet bills. I don't have a savings account because all of mine went towards my house, however I "had" an empty credit card ready for my older babies.
So that's some stuff to think about. From a level-headed cat momma.