This past year's market is not going to be a great comparison point for obvious reasons, but looking at the ESPN FA tracker, only 10 SP got more AAV in free agency than Arrieta. 2 were very good in a full season(Morton, Ray), 2 were very good in half a season(Bauer, Kluber), and of the remaining 6 the only one who exceeded 1 fWAR was Mike Minor and his 5.05 ERA. Trevor Williams had 1.2 fWAR in 91 IP. This is the point, the unspoken inference to 'if only they weren't so cheap' is that they'd have done better if they had just spent more money, when the guys further up the ladder are a pretty big minefield themselves.