I decided to purchase an pre-owned MacBook Pro Retina 15" notebook! I need advice as to which is the best year to look as for the best deal? Not sure if I want a pre-soldiered in components MacBook Pro Retina notebook but I am guess that if I buy it right; I don't have to worry about it upgrading it at all! Basically, like to have QHD screen resolution, 512GB SSD, 16GB RAM and second video card. I know a lot about the PC and notebooks on the Windows side; but almost nothing about the Apple Macbooks Pro Retina at all! I talk with a MacBook specialist at the Apple store and he told me all the components are soldier and that the one he recommended was the 512GB with the higher CPU and additional video card for $2499. I have a few questions to make me more knowledgeable about purchasing this notebook shown below: What year did Apple start to soldier in their components? What year did the most recent i7 Core generation start? 2013? What the difference between mid year versions? Is there a significant difference in speed from 2012, 2013 models including the mid year models and if so which is the best for the money? I was first going to go with a 2014 model but the asking price was too close to that of the 2015 mid refresh! I don't have a dollar amount in mind but thinking about $900-$1,200 range. The new entry level 2015 June refresh starts at $2,000 with warranty; so I figure I can get a full load model a few years old at my price range! That my thinking on this. I saw the $3200 model and was saying what was this model now a couple of years old now! Thanks for any insights on helping me make my purchase! I primarily looking at buying it from eBay! But if there is a better alternative; please let me know!