Getting a second yorkie is the best decision we made. It changed Snickers completely for the better, and we have twice as much love and fun with two of them. They are so entertaining and watching them play together is a riot.
Yes, the vet bills are doubled and the house is hectic sometimes, but it's more fun with two. They are less demanding of your time because they occupy each other when you are busy. There's something about yorkies that makes you want more and more. I'm working on getting a third now! v
If you can afford two, then I would say go for it.