This is going to be one of those niche areas that some may want to do but others may choose not too because normally this is just a P2W feature. That being said, some of the option set bonuses can be very helpful in the later game once you start acquiring certain gear pieces or just your gear in general
Option upgrades will be able to provide you some great bonus stats and boosts to your gear. If you happen to be lucky enough to have a core piece for your sets, this will also boost the stats of those as well!
If you do want to start utilizing Option Upgrades, I would only recommend getting your sets up to +11 as anything beyond that becomes quite expensive.
You will be able to acquire a lot of the Jewel of Life from various events that happen in MU Dark Epoch