Given how little Walker has actually accomplished so far, I'm not sure I'd want to offer Santana for him. 157.1 is his high for IP so far, & he's only controlled for three more seasons. Not saying I think Santana is worth Walker+, but I'd rather use Domingo to go after a better SP. I feel like, if we acquire Walker, we'd burn his three years finishing his development into a 200 IP/yr arm, just in time to lose him to FA. I like the idea of trying to trade for an emerging & not established arm, but no way I'd pay as much as you're proposing for Walker.