Would you sell half your vinyl collection to get great equipment ?


I would if I had a substantial one. And don't say your system is already great, there is virtually no limit, including replacing the house.
inna
And the collection that I had was not the largest ever or anything. But, if I didn't feel pretty doggone confident about a particular potential music purchase, then I knew I might feel better with that money going toward better gear at some point. Still buy music that way even today, really.
I have pondered this question for the last year +/- .  The answer NO.

Virtualy every record was bought with due consideration for budget in the early days. The entire record needed to be great. Took half a decade before I would consider recordings that had cuts that I didn't care for.

As the system evolved; I started only buying and playing recordings that sounded great on it. Of course hundreds that Sounded great on that early eguipment just filled the racks ; not to be played. Maybe tried every so often when I bought a new component, but ended back in the racks. And continued searching for recordings that sounded great on my current system.

Bought this house (6) years ago. Get (2) dedicated rooms. Main and smaller room. In the last 1 1/2 yr. The main system has reached a level that I have dreamed about even though each evolution in the last 25yrs was very good.

Even though I have used acoustic treatments for these 25yrs and the room is dedicated. The flaws of the stinkers and mediocre recordings stood out. For the last year + , I have given treatment of the room and equipment setup high priority.

System and Room are almost complete. Already sounding superb.  Next week, I will receive the final acoustic treatments to complete my room. I pulled a mediocre recording and Surprisingly, it had a lot of its original magic again. System alone could not bring it out. 
System and Room together are bringing the Music back.

Sept 13, 2017 - Received my 1st diagnosis.
Sept 18, 2017 -  Received my Comfirmed diagnosis.

Are the stinker and mediocre recordings audiophile quality now? No; but are very listenable and Enjoyable. (Give them a superior cleaning)

Selling excess equipment; Still buying records. Three (3) this year so far. The Music is forever, equipment changes. The recordings are archival. The Music is there. You just need to complete the entire system. The Room is a Major Component. Perfect Setup is essential. Not "near" perfect; Perfect! It is hard and exacting work. Reward is great.

Sooner, rather than later; a mother lode of recordings will be available and the cycle will continue.

Vinyl, Tubes, Class A and Acoustics Rule.

Best to All on this Journey 
inna,

I agree. Was a sad day when I sold my R2R and threw in the tapes to a guy in Juneau, AK that drooled at the purchase.
Have a R2R that a "picker" friend gave me. Needs to be cleaned / overhauled.
Just not in my cards.

Best