I work on classic vehicles daily.
Just yesterday i needed to pick up some power steering fluid and ATF for a 1973 vehicle i am working on That i just replaced all of the steering components. I was just looking for a cheap Dextron to top of the transmission. What used to be $2.00 is now $7.89. The parts that used to be available at an acceptable price at most part stores like a power steering pump has doubled as well, that's if you can find one.
My guy at the parts store that i have been dealing with for 20 years came out and said yea, parts that were once $30 not so long ago are now $130.
Even if you want to do a service on your automatic transmission its over $100 for just the fluid. An oil change with a good quality oil and filter is just about the same.
It is not getting any better.

I get most of my oil from Walmart and use their brand of oil, I have seen tests of the oil, and it compares to the name brands. I check Rock Auto for AC brand filters, they are usually the cheapest but sometimes the shipping costs more. I also compare prices with Amazon because of the free shipping

I just ordered conventional Pennzoil 30W (as I've always used in the '68) from Amazon.

When I saw it was a case, as pictured, for $38.49 I thought, "wow the price has really climbed." Then I saw the "case" was 6 quarts, not 12 like they were since always. Good grief.

Only Brad Penn or VR1 goes in my engine.

X2 for VR1. Usually Walmart is cheapest, sometimes Menards.
RockAuto has Wix filters about as cheap as anyone.

I just did a search on the parts store i have been using for the past 20 years. Searched for various parts for 1968 firebird. They don't have any power steering parts in stock. Nothing. No gasket sets. only valve cover gaskets and intake manifold gaskets. That's it.
Most everything now has to come out of a warehouse in Phoenix which can take a day or 2.
Here we go

More and more, as the local, real auto parts stores have closed, I’ve been ordering from RockAuto. Good prices and a lot of times order will deliver the next day.

My issue with parts these day, just because i have to deal with this more and more is.
If there is a problem with a part it is the time wasted returning and waiting for a replacement.
At the local auto parts store i always open the box and check the part before i even leave the store.
You would be surprised how many times i have opened the box to find a part that someone already tried using it and just put it back in the box.
It really is a crap shoot on what your actually getting.

I get it. My local stores are “gift shops”. My brother in law turned me into RockAuto. This year I’ve slowly begun buying from them. Yet to be disappointed.

Yes i agree, i have gotten parts from them that no one else had in stock.
I think Rock Auto may be one of the few last places to find some parts after the local part stores finally give up on parts that are 50 years or older.
But another issue of mine is machine shops that are capable of getting machine work done in under a year.