I'd add Lodolo and others to your list (despite no 30 GS) and might go down as low as Mitch Keller, who is more like a mid to a low #2 or high #3, if you use the top 30 grouped pitchers, but I think several can be obtained without giving up the world.
I think we gave up a lot for Crochet, but it worked. Now, nobody was sure Crochet could lead the league in IP, so there was speculation on him, but we should be able to add a high #2 via trade.