"AIBU to believe the presents given should reflect the cost of a do/venue" YES! massively unreasonable! I've always been on a tight budget but when dd was around this age every party she went to the gift cost was approx the same with the exception of my niece and nephews as we're naturally closer to them.
You were rude - apologise and resolve not to be so in future.
"Petty and stingy" geez with friends like you...
Stop being such a snob (and not a very good one actually as true snobs base on quality not price).
You're essentially saying "if you want your child to get a decent gift you have to spend more on the party"
Seems to me you know the cost of your gifts while ignorant to the value of your (and your CHILD's) friendships. I'm guessing you're also the type expects people to spend the same on you for gifts as you do them and if they're not as well off as you, you spend less on their gifts!
Also the cost of the first party may have been more in cold hard cash, but the 2nd party certainly would have required more effort - which is ALSO valuable, or is it only money that matters in your world? Doubly insulting that your gift policy means that you think the effort your friend went to in opening her home and all the prep before and clearing up after isn't considered of value.
Pps are to a degree right that friend was also rude to call you on it - but then I strongly suspect this is a case of "final straw" do you treat this friend and their child less well than the other in other ways? If I'd been her I wouldn't have said anything - but I'd have distanced myself from the friendship as a result!
Agree also it's a very poor way of parenting, teaching your child friends are more or less important based on what they have to offer materially!
"I do appreciate genuine opinions" they're all 'genuine opinions' whether you like them or not! And what courtesy? Given its been pointed out multiple times that actually most consider this BAD manners I think you need to reassess.
I don't actually fully believe the update. I think op may change her behaviour slightly but not her ideology.
"Believes that I base my present giving on what my DC get" but you are - you're basing it on what kind of party they 'get'. I agree your updates are making you sound worse if anything!
You have a good deal of thinking to do I believe, I dread to think how you'll treat a friend of dds if like my dd they come from through no fault of their own, a family who can barely afford a few friends for a sleepover!
Because the extrapolation of such attitudes is that some PEOPLE are worth more than others. That people are only worth what they can offer you in return.
Deny all you like, at heart that's what your 'principle' equates to.