Hello and Welcome to YT!!!! You'll find tons of useful information here to help you be prepared when you find your furbaby.
I would like to caution you on purchasing a puppy that is sooooo cheap. If you know the breeder's breeding stock and they are healthy dogs then great, go for it!!! If you don't then I wouldn't purchase one from them. If they are looking to rehome one for free or it's completely vet checked then good.
Yorkies can have a lot of health issues that will run your vet bills up super fast! Please, consider rescue...not that it's cheaper, but the dog "SHOULD" be vetted and you'll know from the foster family if the dog's personality is right for you.
Please, keep in touch and let us know if we can do anything to help you in your search.