You're not going to get enough for Rupp or Galvis to move the needle, if you don't think they're starters for a 90+ loss team, why would anyone give up a top prospect?
I see this from fans all the time, "do something, anything."
Then when a GM panics and does something, it's usually a disaster and the fans want him fired!
Right now the best thing Klentak can do is be patient, flip some veterans in July, keep restocking with the next two drafts, and keep building up the farm system. The window for big LA spending is past, so spend on scouts and trade for allocations IF the price is right (i.e. you don't trade legitimate prospects so you can sign marginal LA 16 year olds).
Nor is it easy to spend, Desmond got 5y, $70M, starting at age 31, he has a .691 OPS, Saunders got $9M. Both are flops, which flop would you rather have? With that salary, Desmond is untradeable. There weren't a lot of attractive FAs changing teams last year.
Cespedes (31) - 4yr/$110M .992 OPS but has only played 18 games
Desmon (31) - 5yr/$70M .692 OPS
Encarnacion (34) - 3yr/$60M .774 OPS
Turner (30) - 4yr/$64M .965 (3B)
Reddick (30) - 4yr/$52M .775 OPS
Trumbo (31) - 3yr/$37.5 .733 OPS
Morales (33) - 3yr/$33M .763 OPS
Bautista (36) - 1yr/$18M .763 OPS
Walker (31) - 1yr/$17M .793 OPS (2B)
Beltran (40) - 1yr/$16M .712 OPS
Jensen (29) - 5yr/$80M 1.11ERA/0.36FIP
Chapman (30) - 5yr/$86M 3.55ERA/1.42FIP 14 games
Melancon (32) - 4yr/$62M 3.12ERA/3.08FIP
HIll (37) - 3yr/$48M 3.77ERA/4.98FIP 7 starts
Cecil (31) - 4yr/$30m - 5.66 ERA/4.92FIP
Volquez (33) 2yr/$22M - 3.41ERA/3.98FIP