There is only one guy I would sell the farm for and that's Mike Trout. I would still try to be creative in order to avoid giving up all our top young guys such as agreeing to take on a bad contract or swapping out Didi's higher offensive upside and cheaper deal for Simmons but if all they want is our 5 best young guys he's the only player I would do it for. He is probably the best player in the game right now. Most importantly, he's also signed to a long term deal. Sure, its uber expensive but he's the real deal and if we're investing so much treasure in terms of prospects I'd rather pay a premium to ensure we keep the guy we're getting back for as long as possible. Especially when that contract runs through his prime years and doesn't last until he's in his 40's like the A-Rod, Pujols and Cano deals.
Why Mike Trout and not a pitcher like Dallas Keichel, Clayton Kershaw or Max Scherzer? The answer is simple. Baseball's regular season is 162 games long. If you're going to invest a boatload of money in someone and gut your farm system to get them then you need to maximize your return. As great as they are those pitchers will only help your team win once a week. A player like Trout will be able to help you win games every single one of those 162 games. With that being said, its going to be awful painful to watch Keichel and McCullers tag team the Yankees over a best of 7 series but if I were the GM I'd worry about earning the shot to get to that best of 7 rather than worry about how I match up with the Astros if I do get there. In the meantime I'm going to want the best 1-9 possible game in and game out while hoping my pitchers do well enough to keep our offense in striking distance.