Yes, if you want to unlock the stuff that's in the warbond.
In the future there will be more warbonds. So you can also save your uber credits.
But don't worry, as far as I know, all warbonds will be available for ever. So you never miss out on certain items, as you'll always be able to unlock them later on
I realize you can't trust devs typically, but multiple review sites have said everything in game is available forever, and can be attained just by playing. All mtx are optional only. They didn't dick around on the last one, and they've earned a ton of goodwill already.
Id say buy it after you beat the normal warbond (assuming a new one hasn't come out yet). Some of the cosmetics are cool.
The guns are alright (the revolver is interesting, but the machine pistol in the free battle pass is better imo).
It does have more super credits in it, but I can't remember off the top of my head if it has 1000 ( so that it would pay for itself by beating it)