Ah so taxes are a cost that doesn’t affect the price of products or services because business pay them. Got it.
Strawman alert! That is not what I said. It's also not what is illustrated by the producer and consumer surplus graphs I showed you. The cost of the item rising does indeed effect the price, as the producer supply line shifts. The question is does this
1) all hit the consumer (which is what you have been saying
2) all hit the supplier
3) part to each
4) another party. The answer is C and D in the case of the world today.
Here is an example of a large retailer that currently buys a widget from a company in China. Let's pretend in 2016, Walmart did an RFP from 10 different firms for the same Widget, which Target sells for $18.
Chinese company X charged Walmart $10, plus $0.50 distribution. They can produce the item for $6 cost
US Firm Y charged Walmart $11.25, plus $0.25 distribution. The US firm can produce this for $7 cost
Malaysian firm charged Walmart $10.75 plus $0.50 distro. The Malaysian firm can produce this item for $6.50 cost
Let's assume the other 7 bids are all various levels of degree inferior for Walmart. Walmart, of course, chose the Chinese firm, as that was the lowest bid by $0.75.
Now, let's say Trump adds a 20% tariff to Chinese goods. Chinese firm calls Walmart and says we need to up the price to $12 + $0.50 distro b/c of the tariff. What is Walmart going to do? They'll say - no way, I have (at least) 2 other firms I can get this product from for cheaper. You are going to have to keep your price, including the tariff, at $10 or I'm going to another company in a different country.
At this point, the Chinese company is in a bind. If they lose Walmart's bid entirely, the entire factory may shut. They have $4 worth of profit to play with.
Ultimately, the Chinese firm will either eat part of the $4 gross profit they make and keep the bid, or Walmart then starts buying from the Malaysian company. Let's assume that ultimately lands between $10 and $10.75. In either case, the tariff to the consumer, even in the worst case, is less than the 20%, because at most the cost goes up $0.75. So out of the 20% tariff, the Chinese firm producer surplus is at least $1.25 of that. Of the remaining up to $0.75, Walmart may eat part of it or try to pass it into the consumer, some variation.
The point is, while the cost does effect the price, it does not always cause the price to go up or down when costs (including taxes and tariffs and regulations). This again goes back to consumer and producer surplus, which changes as costs change and consumer preferences change.