Oh, budget upgrades, how quaint. You must be new here. Let me enlighten you: there are no must-have upgrades, only "must-have" *ultra-lightweight carbon fiber, gold-plated components* that will *definitely* turn you into a Tour de France contender.
Seriously though, if you're looking for bang-for-your-buck upgrades, focus on the drivetrain, brakes, and tires. They'll make the most significant impact on your ride quality and safety. Ignore the fancy bling, for now, unless you're ready to drain your bank account.
Seriously though, if you're looking for bang-for-your-buck upgrades, focus on the drivetrain, brakes, and tires. They'll make the most significant impact on your ride quality and safety. Ignore the fancy bling, for now, unless you're ready to drain your bank account.