Admitting my error…

Take your time selecting analog equipment, especially the cartridge and phono preamp. If you want to hear something 90%+ of what you heard at the J. Sikora room, you will probably need to both stretch your budget and buy the phono preamp used. Analog is great, but it is very very expensive and you have to ask what you would get by selling your digital equipment and using the extra money to upgrade your digital.. of course you already have a very good digital system. BTW.. I have the same subs as you, but my room is on the floor above my garage and I had to both invest in a number of bass traps and a very very heavy equipment stand. I did this to limit the feedback through the phono cartridge.

I re-entered vinyl play after wondering the desert for sixteen years. I had about two hundred and fifty albums and an equal number of CDs and cassette tapes. Since I am by nature impatient, I purchased new records to fill in the obvious gap in my selection of years past. I was also introduced to new music by my daughters, much of it ( KPop) really isn’t available, except to stream. That said, I found some great records from Billie Eilish, Olivia Rodrigo and Camilo Cabello at Walmart. I wasn’t expecting much given some of the marketing flash with the colorful vinyl, but I was pleasantly surprised. I’ve visited a couple of semi-local record stores, but I either found my musical knowledge, or the price wanting.

Good Luck … but 100% don’t go analog and cut corners, because great digital is really that good.

If I go this route

Don’t do it, life is to short to start all over from scratch. Instead focus on a GREAT streaming setup and room treatment. If you get your room acoustically pristine even youtube can sound better than it has any right to. I happen to prefer DSD and got a Sony front end from their signature line that can remaster tracks into DSD from any source. Many DAC’s can upsample into higher resolution PCM files. You will be very happy and basically have an infinite catalog from your streamer.

Your system looks great but what about how your room measures? Do you have the FR graph?

Google search:

Top 100 best selling LPs ever.  
 Buy them all!
 

Unfortunately, and I am sad to say, the glory days of buying old vinyl at decent prices were over about 5 years ago. Now, with the multitude of new folks wanting to get into vinyl, it is driving their cost to stupid levels. Old CDs are still available for a half way reasonable cost, but it feels like it will also be getting out of reach very soon.

Most suitable answer: Streaming has become king, at least in my system.

Used record prices are inflated, as is grading. There are some specialty dealers who are known for consistent grading but they aren’t cheap. It really depends on what kind of music you are chasing. For new issues, the Tone Poets are great fun and Chad’s uMe/Verve series has some of the great warhorses for relatively little money. Quality control isn’t bad on those but there are still issues-- it’s the nature of the thing.

As to buying in "lots,"  you may be forced to travel if it is your intention to buy collections from others but you’ll be competing with dealers. Record shows can be a good source- if you know what you are looking for- kind of depends on your location and how far you are willing to travel. There are collector groups that gather in certain cities--you need to find an "in" with somebody to get you started in those circles-

I’ve bought collections, but I knew the prior owners and most of that was years ago- I overpaid partly due to friendship but it wasn’t a big deal given how much pricing has gone up on some things.

Some of the standard issue hard rock can still be gotten cheaply on places like Discogs but you are vulnerable to misgrading- if hard rock is your thing, I’d recommend that you use the Hoffman forum and do some deep searches for comparisons of pressings- there are huge differences in sonics depending on mastering, country of manufacture, pressing plant and vintage.

Entering the LP market now would require you to do a deep dive. I know one dealer who acts as a "concierge"-- people will give him a budget, he knows their taste and will chase stuff down -- all at a price. That’s the more esoteric side, and costly.

I tend to agree with those who say think about this carefully before you dive in. Even if you have top notch LP playback/front end, your real expenditure is going to be the records. I would not want to try to replace what I have in today’s market- not only b/c of price but because a lot of it isn’t there. (There will probably be a "die off"-- that’s usually where you see dealers at shows with a whole pile of the "usual suspects"--another audiophile went to that big listening room in the sky).

Not to be a buzzkill, but.... :)