Battery - for KTM 300

I need to fit a new battery to my 2015 KTM 300 XCW...... From KTM is option of standard lead-acid replacement @ around R525 or Lithium Ion battery at 3 times that price, which apparently also then needs a special charger if you want to charge it, but apparently is muuuuuuuch better. It certainly is much lighter.
Or a cheapy R285 battery from the local general battery dealer down the road.

Any advice ?

Are there different quality batteries ??

Regards
Rory