Save or spend?

I REALLY want the pv costume, but I have the worst luck when it comes to the legendary costume gacha, I haven’t gotten a single legendary costume from this one (I usually get them in the regular gacha)

So my question is, is it really worth spending all my cubes to try and get this one outfit? Or is it better to save them until the outfits go to regular gacha or see what ones are being released in the new legendary shop ?

Any advice is welcomed 🙏