[hcarvalhoalves]

I suppose it takes a lot of deltaV to get a stable orbit over the sun poles?

[perihelions]

It's doable with gravity assists. Ulysses got up to 79° inclination using a Jupiter flyby.

https://en.wikipedia.org/wiki/Ulysses_(spacecraft)

[sandworm101]

It does, but most of the needed dV is harvested from the planets during gravity assists. The probe is accelerated/turned several hundred or thousand m/s and in exchange the planets it passes are shifted/slowed/turned by maybe 0.00000000000000000000001 m/s. In this case, the probe largely needs to slow down, to bleed of the speed it got from being at earth's orbit, so the planets are probably being accelerated.

[ChocolateGod]

You'd need to completely cancel out the rotation of the solar system, far beyond what we have the technology to do.