Alright, let's look at this from a non backwards, "back in the good ol' days", unbiased view.
So early game wards are the problem, eh? Having a ward top and a ward bottom breaks the balance? Is this just because of trilanes where both supports go to the same lane? Because is 2-2-1, you will have a support in two lanes, one has access to both lanes, thus able to ward both lanes. So you have all 4 wards bought anyways, warding both top and bottom locations. How is this less balanced? And What about the tri-lane? do we really need more incentive to build tri-lanes? Isn't a minor "change" that breaks tri-lanes a good thing?
But what about the pull spot, you have to buy at least two wards to ward it in a stack. yeah, and you have to buy at least two rev-wards to counter it if it is warded. So not only are you already requiring a flying courrier to spot it, you also need to buy rev-ward stacks, another 200 gold. So while it's "more difficult" to ward the pull, it's also more expensive to counter a blocked pull. If having the pull blocked is the issue, why would you make it equally (or more) difficult to counter it?
But counter warding is rewarding; they get a whole 50 gold for killing a ward of sight. Yeah? And? Counter warding is important, but they're spending 100 gold to "possibly" counter it, with proper observation of your enemies you can up that possibly to a "probably". But observation of your enemies requires you to have wards up anyways, so you're spending time out of lane, money on wards, and time being observed by that ward, to counter their information gathering tools, and giving a small reward that doesn't even cover the basic costs of the tools to counter it is a bad mechanic for rewarding you for having superior information gathering abilities? riiiiiight.
What else is broken about early game wards? Is it because people may start warding and counter warding sooner? Is it because it encourages player interaction? what else is changed by the fact that you can buy wards 1 at a time instead of being forced to buy a 200 gold stack. Early game money doesn't exaclty flow freely, and every bit you get is awesome, it's not like supports have a ton of money to just throw around freely.
And you want to nerf supports. Of all the things in the game to nerf, you choose supports? It's not like we have a problem with out of hand semi-carries, items that are generally unhealthy for the game, a playerbase that is worse than the whole of 4chan, a competitive scene that is stagnating because there are too few people actually willing to try something new, and a bunch of people so set in their old habits that they want to change everything back to the way DotA handled it because any change lowering the skill floor that could possibly help any player out that hasn't spent over 1000 hours of their life playing MOBA games is blasphemy. Lower the skill floor as far as possible, so anyone can get it and start going, but keep the skill ceiling high, so those who invest the time and effort into learning the game will obviously outperform those who haven't.
So the final most important question. Has the skill ceiling for placing wards been affected at all by this change? Because if the only change is the skill floor, I'm more than happy to keep things "easy" and logical.
I think the main argument for it costing more to counter blocking the pull spot is simply because of the power of it. The pull spot can if used correctly completely drain an enemy player of an entire creeps worth of gold and experience whilst boosting your own at the same time as well as pushing the lane towards your own tower. So to block it you invest essentially 100g of your own to stop the enemy from being able to take more in the future. Back when wards were bought in two's usually it would lead to the support warding the rune and the enemies pull spot, the enemy would then NEED to have bought 2 counter wards and place it and kill it (using the flying courier). The other team would then need to buy another 2 wards so another 200g to reward it if they felt it was necessary. This starts leading to opportunity costs because you would have to wait at little bit to get the gold for the next 2 wards and the 2 counter wards (in order to make sure you aren't just immediately counterwarded again) in exchange for blocking their pull again .
Basically the biggest issue with wards atm is how easy it is to counter the pull ward?
Making the pull unpullable, or unblockable, will kill certain strats and/or lineups. But having a triple stack deny multiple waves is pretty strong.. only real counter to that is by pushing the tower down early?
Btw, I wanted to point out how easy/strong/possibly imbalanced deny heroes are for lane control. Especially pr. (I felt this kinda goes hand in hand with this topic, since you can't prevent these actions that influence the waves)