Earlier quoted context omitted.
The absolute amount of money is irrelevant, it matters what percentage of a person's disposable income it is. $10k is nothing if you making half a million dollars a year and have $200k in credit with no balance, because your disposable income is probably $400-450k/yr. $200 is a ruinous amount of money if you make minimum wage and take the bus to work because your disposable income is very likely negative.
Yeah, well if someone can't swing $200 they probably shouldn't own a pet.
Caring for a pet has a cost. The obvious cost is its nutrition, but its health costs must be accounted for as well in the decision to acquire a pet. No matter if you pay a lot for the pet or get it for free, now you have full responsibility for this life. It lives in your captivity, so it's your responsibility to ensure it's being cared for. This is not nature, it can't just live on its own and take care of itself as it would do in nature. It's essentially your prisoner, even if it's rare to see anybody understand that, so you need to provide to its needs. Including health needs. And that incurs a cost. Not _if_ it's needed, it's _when_ it's needed. If you can't "swing" that, then your decision to own a pet was an unbelievably irresponsible one.
The hate shouldn't go towards the vet charging that money for treatment, but towards this irresponsible pet-owner-who-shouldn't-be-one. It's irresponsible mainly towards the pet, but even towards the vet, as the original article demonstrates quite well.