Yeah, baseball prospects are picked young, and can really take deep paths to make it. Like Hope was an 11th round pick, traded to the Dodgers in the Michael Busch trade a few years ago, and then developed into a better prospect. De Paula, the Dodgers other top prospect, was a mid tier international signing. It's a lot more about scouting and the quality of your development programs.
Gausman is a good starter, so I would think he could bring back a top 50 guy. I mean, I think even if you're only getting back someone in the back half of the top 100 prospect list, it's probably still worth it, rather than hang on and maybe hope that you can sign him to an extension. It's really going to come down to how many other starters are being moved, and how many teams are buying.
Varsho yeah has history, so a QO on him is on the table. In that case, you need someone to overpay for him. Hoff hopefully someone will give you a good return - you can keep him since the team definitely should still look to be back in contention next year, but especially with the pending lockout, I think you don't worry as much about the control.
I think you still trade guys like Springer and Bieber for lotto tickets. More tickets is always good, and the team isn't going anywhere. But yeah, you're not getting that much back for any of them, if nobody bites, so be it.