According to Sam Walker, the Seahawks are Holding the Line on Defense Spending:
Based on an examination of league salary data that aren’t released publicly, the Seahawks defense cost the team 30% less than the average for the National Football League. In fact, Seattle spent less than all but three of the league’s 32 teams.
Both the Seahawks and Steeler spent money on linemen:
The Steelers and Seahawks both spent lavishly on offensive linemen: Their $30 million investment here was about 12% above the NFL average for that position (both teams finished in the top five in rushing and together allowed fewer than two sacks per game). The teams each spent about 10% more than the NFL average on tight ends, too, another strength on both rosters. On defense, both trailed the league by 26% to 42% on cornerbacks and safeties and, perhaps as a result, posted average or subpar numbers in interceptions and passing yards allowed.
The teams that ended up in the big game both picked up some undervalued players:
Like most NFL teams, the Steelers and Seahawks allocated about 40% of their payrolls to just 10 star players. But they also drew strength from the underpaid: According to an advanced “dividend” formula created by Protrade, an online fantasy-sports company, Pittsburgh’s Willie Parker produced almost four times as much value as a typical NFL running back, while Seattle wide receiver Joe Jurevicius produced double the normal productivity. Each player took up less than 1% of his team’s overall budget.