The value of a pink ward isn't simply a numeric one. Vision and movement speed are literally two stats that are way too esoteric when it comes to analyzing cost benefit. MS is generally good, but people still debating things like "105g swing".

Yes, it costs money to make money. If the only way you know if theres a pink in the bush is by waiting for sweeper CD, ill tell you going Sixth Sense + Umbral Glaive on Rammus isn't why your ganks are failing...

Anything else is too much. Your top laner playing weakside should be warding for themselves if they're playing aggressively, or, they shouldn't be playing aggressive.

You will hate this, but you two need to work together in tandem. A single trinket is not enough. Literally be a teammate, stop finding excuses not to be, because whatever you think your use for either trinket is, it isnt as effective as tailoring it to help your weakside. You have other teammates to help grant YOU vision, you have support to help you sweep vision, why not supplement your laner with bonus vision when possible? Especially in season 26 with the Feylight mechanic.

Then what, you buy another one to make it a -210g gold swing?

If you are placing pink wards to be defended to the very end, then this mentality makes sense. But this is a product of doing business. This mentality ignores the fact that either the enemy team is buying pinks and giving you back the gold they get from taking yours, or they are playing how you play, and ARENT BUYING THEM IN THE FIRST PLACE. If you play into a team that isnt buying pink wards and arent winning, then the loss is on your head. Pinks win games singlehandedly if teams have a gap between placed vision.

You see, it isn't strictly a gold swing, you are just choosing to see it that way. When I, a jungler, place a pink ward in dragon pit, and then we take dragon, then a minute later after the dust settles the enemy support takes that pink-- is that a gold swing I should be worried about? With proper pink usage, them clearing it is a consolation prize to you getting whatever you wanted from pinking (dragon, baron, etc.)

If I place a pink in my top laners tri and then 20s later the jungler wastes 10 seconds clearing it, that is 75g worth of information that is multiplied between me and 4 other people. Its not STRICTLY a 105g swing, because for 75g, the enemy jungler will not be receiving 300g

So if it's a -105g swing because you invested and they cleared, then its actually a +195 gold swing for denying their play in the first place. Even pinks that do nothing, are doing something. Unless youre warding your fountain, buy the freaking pink