> If you are shopping for someone else's kids, how hard is it to talk
  > (/text/email/etc.) to the parents about the kids interests?

Or even talk to the kids about the kids' interests (with written permission from the parents and social services and in the presence of at least three independent board-certified chaperons, of course).

How? There are kids in my child's class at school I've never met; I don't know their parents and in some cases there are never occasions where we share geographical location (their kids are picked up by carers). Schools don't give out the parents information; relaying contact details through children under about 8yo is impossible.

Then what? Arrange to meet them at their home to talk to their child for 30s about what they want for their birthday (that's in my price range) - the whole process is costing more than the present at this point.

Am I right in thinking you're not a parent?

Asking a parent you know for ideas for a party present for a kid is quite reasonable, asking the child won't help unless it's a child you're close to and you're spending a considerable sum and I'd warrant know the child's personality pretty well.

a bit harder than just having the filters.

> a bit harder than just having the filters.

But, given that kids that don't conform to gender stereotypes of interests exist, probably infinitely more useful.

Heck, even for kids that conform to gender stereotypes to the extent that all of their interests are within the scope expected for their gender, its still vastly more useful to get direct information from them or their parents about their interests, because its very rare that any kid's interests will be cover all of what is within the gender stereotype even if it is contained within the gender stereotype.