Well, what i have to say to that is: The more, the meryer.
I have 3 ConneXions, one P2 and a Nano puppy. And, by the end of 3 months, i plan to have 21 tamagotchis. So, you are not mad. And, if you love something so much, then, well...go for it!!
i think its a great idea to have 4 tamagotchis. is it hard to take care of 4? i just got my 2nd tamagotchi just now. I love taking care of 2 tamagotchis.