Upgrade means different things to different people with diff needs.

For me, an 'upgrade' in tires meant buying the rather expensive Continental Grand Prix "4 Season" tires, which have been really bullet proof when it comes to flats. I don't care so much about weight (I'm not racing against anything) as I care about avoiding some flats on sharp gravel roads.

Likewise, some folks might think an 'upgraded' lock is one that's lighter weight, others might 'upgrade' to a heavier lock instead.
It all comes down to individual needs in your particular situation.

Upgrading based on price is not reliable either, since many bike accessories are vastly overpriced from one seller and a bargain from another.