From my experience of owning Amigas...
If an Amga 3000 or 4000 has sat unused and not maintained they will have issues.
If the 3000 has had the battery removed before any leakage the will run just fine. The only other item that really should be taken care of are the PALS. I have seen them fail, but they are readily available and socketed. I have 2 3000 that have never failed with no battery damage. I have seen 50 or so 3000's fail because of battery damage, they will fail and will have to be repaired I will guarantee it.
The 4000 will fail because of the caps and the damage they cause to surrounding areas.
A well maintained and updated Amiga has a lot more value to me since I don't have to monkey with it or send it out to be fixed. Finding repair talent for the 3000 is a harder job than the 4000 for sure also and should be factored in the purchase.
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