Regarding relievers, I have tried many strategies and overall I think past the 1.2M mark, most of them are just too expensive. In a recent league I tried a bullpen of 4 strong relievers with no specialists and my 6M guy with a godly card had a 4+ era, which is often what a 1.5M reliever gets. It just doesn't seem reliable enough IMO.
One thing that drives me nuts sometimes is how many losses happen in the 9th inning, it's unreal at times. I can feel it coming. I put in Choate and Bradford, etc and they seem to give up a hit or walk immediately and way more often than expected. Then the damn platoon teams (half of the teams generally) keep pinch-hitting over and over and force Hal to leave the specialist in against an opposite-handed batter. Due to the extreme offense spike in the 8th and 9th innings most relievers struggle to have a good ERA, meanwhile the starters seem much more reliable.
But this is just more of why I hate platoon teams, lefty platooners are ridiculously underpriced IMO. Beating a dead horse here
Aside from that, I wish expensive relievers were more consistently worthwhile.