Priority Mail International arrives in 6-10 business days (actual number of days may vary based on origin, destination, and customs delays) and offers tracking of the package and delivery confirmation. USPS 1st Class International can take 10 days or it could take 3 weeks to arrive, there is no tracking available and there is just no way of estimating how long it will take the package to arrive. Once it leaves the United States it essentially does not exist anymore in the USPS system.
Yes, it is considerably cheaper to ship with 1st Class International and if you understand this option and are not in a hurry and want to order, feel free to message me and I will be happy to set up a custom listing for you.