Those other factors aside, I don't understand how tariffs significantly affect Metro's business. Reciprocal tariffs are applied based on the country of origin (not the country of shipment) Transformers are from Heyboer. An American company. Have their prices gone up significantly due to tariffs on steel? I recently bought some transformers from them and the price was about the same as it's always been.
Wire? Plenty of sources for wire and an insignificant expense. Resistors? I haven't seen a major increase in the price of generic carbon film resistors at any suppliers I use. Capacitors? I don't know what they use. SoZo? IC? Vishay/ERO? Probably SoZo. Don't know the price history of those, but probably a few pennies per cap increase if anything. Pots? Jacks? Tube sockets? Screws? Where are the major price increases manifesting? All of these things are available in the USA. It's not like Metro is buying from suppliers in another country... And if they are, there's the problem.
The tariffs on goods from China are 10%. You buy 1,000 resistors and you have to pay an extra $10. I don't think that's gonna kill a business. That will build 100 amps... Sure all the little things add up, but I don't see a couple hundred dollars amortized across 100 amps eating into profits enough to put a business under. If tariffs added $300 for bulk parts as a whole, that's only a few dollars per amp.