The bottom line is that it's hard enough to acquire star or superstar level players. You should focus on keeping the ones you have, while being smart with your cap to maintain flexibility to open a championship window. Maybe let a decent OG walk in FA so you can pay a star. Or sign some cheap backup RB's instead of dedicating a ton of cap to the position.
But no team, and I mean, no team, ever wins a Superbowl without a star studded cast. Letting them walk because they cost a lot is unforgivable.