I fell short of 1K for 2013 by 3600 miles. United has sent me an email with offer to purchase premier miles at a cost of approximately $1700/4000 miles. I travel internationally about 2-3 times per year (sometimes on partner airlines). My questions are: 1. What are the advantages to upgrading besides the 6 global upgrades. 2. How easy is it to use these upgrades....is there any reason that they could shut you out of using them? 3. Can these upgrades be used if the lowest priced economy ticket is purchased? Thanks so much for the help...I am still fairly new at this.