[TABLE=width: 153]
[TR]
[TD] Prospect
Grade[/TD]
[TD]Value (Hitters)[/TD]
[/TR]
[TR]
[TD]75[/TD]
[TD]$175M[/TD]
[/TR]
[TR]
[TD]70[/TD]
[TD]$107M[/TD]
[/TR]
[TR]
[TD]65[/TD]
[TD]$70M[/TD]
[/TR]
[TR]
[TD]60[/TD]
[TD]$60M[/TD]
[/TR]
[/TABLE]
https://www.fangraphs.com/blogs/valuing-the-2017-top-100-prospects/
So Bo's value is probably something on the order of $60-107M.
Yelich's Value
[TABLE=width: 563]
[TR]
[TD]Year[/TD]
[TD]Salary[/TD]
[TD]Age[/TD]
[TD]pWAR[/TD]
[TD]pValue[/TD]
[TD]Surplus value[/TD]
[/TR]
[TR]
[TD]2018[/TD]
[TD]$7,000,000[/TD]
[TD]26[/TD]
[TD]4[/TD]
[TD=align: right]$36,000,000[/TD]
[TD=align: right]$29,000,000[/TD]
[/TR]
[TR]
[TD]2019[/TD]
[TD]$9,800,000[/TD]
[TD]27[/TD]
[TD]4[/TD]
[TD=align: right]$38,000,000[/TD]
[TD=align: right]$28,200,000[/TD]
[/TR]
[TR]
[TD]2020[/TD]
[TD]$12,500,000[/TD]
[TD]28[/TD]
[TD]4[/TD]
[TD=align: right]$40,000,000[/TD]
[TD=align: right]$27,500,000[/TD]
[/TR]
[TR]
[TD]2021[/TD]
[TD]$14,000,000[/TD]
[TD]29[/TD]
[TD]4[/TD]
[TD=align: right]$42,000,000[/TD]
[TD=align: right]$28,000,000[/TD]
[/TR]
[TR]
[TD]2022[/TD]
[TD]$15,000,000[/TD]
[TD]30[/TD]
[TD]4[/TD]
[TD=align: right]$44,000,000[/TD]
[TD=align: right]$29,000,000[/TD]
[/TR]
[TR]
[TD][/TD]
[TD]$58,300,000[/TD]
[TD][/TD]
[TD]20[/TD]
[TD=align: right]$200,000,000[/TD]
[TD=align: right]$141,700,000[/TD]
[/TR]
[/TABLE]
So basically unless you think Bo is going to be a 75 OFP guy, you should be willing to move him for Yelich. Even if you think Bo is a 70, which is probably generous, you should be willing to do Bo+.