This very thing is something I am considering too, one of the first things that occurred to me in terms of an immediate personal effect. I do think there might be a short term spike in people purchasing parts a little sooner to beat the tariffs followed by a drop off similar to a cliff after the beginning in the new year(or whenever it kicks in).

I think the people who are saying the tariff should not be marked up by the supplier are missing a fundamental point. Let us use the example of the mythical part mentioned that costs the supplier 1500 to have it landed in their warehouse. Some of that 1500 is amortizing the engineering costs to design the part. Some of that 1500 is the manufacturing labour. Some of that 1500 is the raw materials. Some of that 1500 is the packaging and handling. Some of that is the ocean and land shipping to get it to the warehouse where hopefully somebody will buy that part at your let's say 25% markup. We will use that number as it is the same as the tariff. The person selling the part does not see their 1500 + 375 = 1875 until the part is sold. That means that 1500 that is tied up in that part can not be used to develop new parts until it is freed up by someone buying that part. Now, the 25% tariff is added on to that part when it arrives into the US. It is not a sales tax added on to the part when it is sold to the consumer. That means the cost to the supplier is now 1875 for the exact same part. All other costs are the same. No value has been added to it, that 375 is just a tax. The supplier has to front that additional 375 until the part is sold. That money is tied up, it can not be used, for example, to hire engineers (most likely in the US) to design the next generation of whatever until that part is sold. It is now a cost that is no different than any of the other costs to manufacture the part. The markup has to be added to the full cost of 1875, which means that part now will cost 2343.75, not the 2250 that it would cost if the tariff was applying in a similar fashion to a sales tax, where the consumer pays it at the time of final sale, not fronted by the supplier. This final cost is still considerably more than the 1875 it will cost without the tariff.

I would love to buy US for all the parts. If someone can point me to a manufacturer in the US that is stamping similar cost, quality and range of sheet metal to AMD for a 70 Road Runner I will gladly purchase from them.