Older Electronics - When to cut bait? Your thoughts?

Hi - I am looking for your collective insight and advice.  I have a Conrad Johnson PFR preamp and MF2250 amp from the early 2000's.  Ironically, I purchased them because of their CJ tube sound AND yet they were more "maintenance free solid state" vs tubes.  Well, here I am approximately 20 years later and I repaired my PFR preamp for approx. $600 two years ago and my MF2250 just went out.

My question is, at what point is it prudent to cut bait and give up on older electronics before they become a money pit?  In the back of my mind I wonder when the PFR will go out again with some other problem and I am looking at another $600 repair.....by then I would be in it for $1,200 of repairs and that is a good chunk towards a newer model.....PrimaLuna for instance.  I am now very fine with tubes as it seems easier and less costly to replace tubes and I really a warm full sound.

For context, I love(!) the sound of the two units although I expect the same, if not better, can be had for a few grand each with lower risk of repair in the next 15+ years... Again, like a PrimaLuna.

Lastly, I know there is not a hard and fast rule here and the answer is subjectively unique for everyone although, I expect some of you have been down this road before so I would love to get your thought process and logic.  Your personal experiences can help inform my thinking as I ponder what to do.

THANK YOU!  Dave

For added context, although I am not sure it matters, I have:
-JanZen Valentia speakers
-McIntosh CD player, MCD205
-Linn LP12 will just about all the upgrades....money pit here:)
-PS Audio DirectStream DAC
-Moon Audio, Silver Dragon interconnects
-Whatever speaker cables....someday will get something else