Wheedus
Team Captain
The reason is if you've got your rookies at ~$180k they may only have ~$120k to make for you. Whereas you get rookies at sub $100k and if you pick the right ones they'll make you close to $200k.
Also, be wary of the impact of the sub. Guys $150K+ are priced at 36pts+ I rookie playing only half a game will be unlikely to score far above 40. Not much scope for price increase there so I wouldn't be treating any of those guys as cash cows. Swallow is a slightly different prospect because he's more likely to get genuine game time from Rd 1 but there are plenty of others who may not achieve the price rises you're expecting nothwithstanding they're playing regularly (particularly in the early part of the season)