You can unlock all the in-game rewards in Resident Evil 2 if you pay £4 - including infinite ammo weapons.
The Resident Evil 2 - All In-game Rewards Unlock, as it's called, instantly unlocks a raft of extras that can also be unlocked through gameplay. It's available on Steam, the PlayStation Store and the Microsoft Store.
For your £3.99 you get The 4th Survivor and The Tofu Survivor extra modes, the unbreakable combat knife, the Samurai Edge handgun with infinite ammo, the LE-5 submachine gun with infinite ammo, the ATM-4 rocket launcher with infinite ammo and the minigun with infinite ammo, as well as costumes, models and concept art.
This is all stuff you can unlock just by playing Resident Evil 2 - so what you're paying for here is a time or work-saver. The main draw has to be the infinite ammo weapons though, as these require a lot of work to unlock and they're a lot of fun to use.