I guess Miller being one of the largest manufacturers of complex electronic (welding) equipment in the world is just trying to rip people off.
Dave, I'm going to get a bit long-winded here, not to disagree with you, but to explain what I've seen when it comes to the price of electronic repair parts so folks don't think they're getting ripped off per se.
It's easy to think Miller is trying to rip people off but I also think Miller has to cover costs (and still make profit) when stocking one-off, custom parts made many, many years ago. Since yours had the Continental gas engine, I assume it's 1970's machine so maybe one of the original designs? I'm sure Miller went through iterations and "upgraded" bits and pieces that probably included the diodes so the "correct" diodes may be fairly rare stockage. As I said before, stud diodes are pretty common but when you add the pigtail as a custom detail, it changes the equation significantly.
Think back 50 years on this. For a custom diode used on a manufacturing line (i.e. when Miller was actively making/selling the Big 40), Miller would ask a manufacturer to do a run of 80k or so pieces (to make 10k Big 40s plus have another 20k diodes in stock as repair parts, etc.). In addition to setting up the custom line (some custom dies, jigs, etc.), this would include some testing and verification of parts to ensure the 80k worth of parts were meeting spec. The price per custom diode is probably just slightly more expensive than the regular diodes but Miller rightly believes the slight increase in price is justified because it reduces the cost for assembly. To buy the diodes, Miller has to pay cash.
Fast forward 20-30 years when that stash of repair diodes is used up and Miller wants another 30k of those diodes to keep those original, old Big 40s running. What are the odds that original electronics manufacturer hasn't moved operations from the US (or more likely Japan) to China? Are those custom dies still available? Setting up a new line and validating it adds up in costs per part....and Miller again has to pay cash for those diodes knowing they will mostly sit in inventory and trickle down over the next 10-20 years at best. So when the guy in charge of telling Miller when to buy/stock 30k custom diodes that costs Miller $20-30 bucks a piece to make (probably a cool $1M for 30k batch after testing, packaging, shipping, tariffs, etc.), he has to justify to the bean counters why spending $1M of cash today will be profitable for the next 10-20 years instead of putting it in the stock market that will probably generate 3-5x in returns. So the Miller bean counters tell the Repair Parts guy to sell those diodes at 10-20x, or even 50x the manufacturing price to ensure the original investment of $1M is paid back fast. Does the Miller repair parts guy, or even the bean counters, like this math? Probably not but it's also reality.
Now think about this conversation happening for each of the hundreds, if not the thousands, of custom electric bits and pieces Miller's used building all those different models and size of pretty blue spark machines. It's not an easy equation to figure out so the bean counters want to recoup their money fast to avoid risk. For example, what if all those those big 40's get outlawed because of some new emission regulation banning 30+ year old equipment or if there's a new electrical hazard requirement that suddenly makes them "dangerous". Yeah, bean counters are skittish people with their money books so they over compensate with high prices where possible.
Anyway, the point of this long-winded explanation is to show that a guy like Fastline can come in with a better solution for those custom repair diodes using current off-the-shelf parts at a LOT cheaper than Miller ever could. For one, he's just using mass produced parts that have the same specs. Second, he's not doing a lot of testing, marketing, and warranty on those parts so his costs are low. And lastly, he's not having to buy truckloads of diodes at a time, he's just buying standard parts at standard costs when he needs them. And now Fastline just sets up his Tik-tok, Facebook, eBay, Youtube, Amazon, etc. advertising and store fronts for dirt cheap compared to Miller having to use their own expensive brick and mortar warehouses and computer tracking systems.
So while Miller has to charge high prices to even provide those parts for sale, Fastline can come in way lower with a different solution. It appears Miller is trying to rip us off compared to Fastline...but maybe it's also because Miller has to charge those prices just to stay alive. I'm not trying to justify a business ripping off customers, I'm just explaining some of the internal discussions I've dealt with in my many years of making computer chips in a previous life.
Speaking of making profit, I gotta get busy on my side making real profit as sitting here banging on the keyboard isn't doing it
