Gutters are not weak, they wont cry or bend.

This is extremely bad advice. Most aluminum or PVC gutters are poorly
installed. And even when they are properly installed they most certainly
WILL be likely to bend. The amount of pressure applied by a person going up
that ladder is more than likely to cause the point where it contacts the
gutter to deform slightly. Combine that with even a slightly uneven footing
and DOWN goes the ladder. Someone that goes up ladders for a living might
have enough experience to gauge just how much movement is safe. But the
average homeowner does not have that sort of experience and should not be
taking that sort of risk. Especially when it's so inexpensive to get decent
stablizer.

What is important is saftey,

SAFETY is certainly important. Just get a ladder extender like the one
mentioned in another post. Or like one of the other stablizers show on the
that website. Let the ladder rest securely against a surface that WILL NOT
move. Don't half-ass it.