The last day 1 or 2 pick that got a 2nd contract from the Patriots was Duron Harmon in 2013.
Right, but my point is that this is more because of poor drafting than it is cheapness/reluctance to pay guys. Over the close to decade and a half before that they drafted well and consistently re-signed guy because they were good to great to even hall of fame caliber players. They re-signed guys like Richard Seymour, Matt light, Ty Warren, Vince Wilfork, Logan Mankins, Jerod Mayo, Sebastian Vollmer, Devin McCourty, Rob Gronkowski, Donte Hightower. That's a long list of players to re-sign from rounds 1-2 and pretty much all of them got deals at or near the top of their positional market. That's not even to mention the day 3 guys like Tom Brady, Jarvis Green, Dan Koppen, James Sanders, Stephen Gostowski, Matthew Slater, Julian Edelman, Aaron Hernandez, Marcus Cannon that they re-signed. Sure, they let a lot of their draft picks go when they became free agents, but they also kept a ton of them. They went 20 years with loaded rosters across the board. When you're stacked at every position like we mostly were for 2 decades you're going to have to let a lot of guys go. But
Since 2014 we haven't drafted well at all in day 1/2. In 2014 Easley was a total bust and Jimmy G couldn't be kept on a 2nd deal because we still had Brady. In 2015, Malcolm Brown was a good starter but also someone it made sense to let go because his deal was up at a time we still had a loaded roster with better guys to allocate money to and Richards/Grissom were 2nd and 3rd round busts that year. In 2016 Cyrus Jones was a bust, Thuney ended up franchise tagged (which I guess is technically a 2nd deal), Brissett was traded because we had an overkill of QB depth at the time, Vince Valentine had a good rookie year then tore his ACL and didn't make the team after that. In 2017 we only had 2 picks in the top 3 rounds and took Derek Rivers (tore his acl multiple times) and Antonio Garcia (who got cancer as a rookie and couldn't regain enough weight to play OT in the NFL). In 2018 we reached for Michel to fill a need, missed on the Wynn pick and totally whiffed on Duke Dawson. In 2019 we drafted a bunch of busts besides Damián Harris who is very "meh" at a replaceable position.
Again, I don't think the lack of extensions is because of cheapness. It's because from 2014 to 2019 we drafted really, really poorly in rounds 1-3. It's that simple. We had some better success on day 3 where we've retained guys over that stretch like James White/Shaq Mason/Ted Karras/Deatrich Wise.
Now it's the 2020 class that's up for the extension decisions and there are some guys who are good players in Dugger/Uche/Jennins that might be re-signed. 2021 has Barmore. 2022 looks rough right now. 2023 is waaaaay too early but seems like Gonzalez and White will be good players IMO.