Upgrade ARC Ref 5 to Ref 5 SE, which path?

Would it be better to pay $3100 to have the ARC Ref5 upgraded to a Ref5SE by the factory...or sell my unit and buy a new one for top-up of $6500?

When I resell the unit...will a brand new, higher serial number unit perform better assuming all other factors are the same?(Tube Life used 2000 hrs , other parts--will they degrade?)

Come re-sell time..will a new from factory Ref5SE fetch a better price than one upgraded from the Ref5?
Personally I would sell the ARC Ref 5 and then purchase a new Ref 5se. A 'new Ref 5se on the used market, say three years old would probably fetch around $7,000-$7,500. It would likely get more than a re-modded upgraded original Ref 5 converted to Ref 5se.

My opinion is based only on re-sale as I would imagine sonically, they would be identical. If you can purchase a new in box Ref 5se for $6,500 (including selling your unit) then financially it would be almost the same as spending $3100 for an upgrade. So things being financially even on the front end, I would go for the new Ref 5se.
How much do you expect to get for your Ref 5?
I own an upgraded Ref 5 SE. Bought it as a Ref 5 for about $7200. ARC did the SE upgrade for $2500. So my "all in" cost is $9700. From a quality or resale perspective, I am indifferent that my Ref 5 SE was factory upgraded. In a way, I'm happier with the upgraded version because it was substantially broken in. Qualitatively, ARC will not let an ARC branded item leave its shop unless perfect.

In your case, the bottom line is cost and convenience. If you can flip the Ref 5 and get a good price, obviously that reduces the buy in for a new Ref 5 SE.

When you say the "top-up" is $6500, I assume that is the extra cost after you unload your Ref 5. Just guessing here ... but I surmise you might be able to get a new Ref 5 SE for 15% off MSRP, or $2600 discount, leaving you to come up with $10400.

Keeping the numbers round, say the new buy-in is $10,500. I guess you might get $6500 or so for old Ref 5. So the all in price for the new could be about $4000, maybe a little less. The cost of the $3100 upgrade is still less.

So the decision will turn on convenience. ARC took a couple of weeks to turn my Ref 5 around. But as Kal explained, ARC literally remanufacturers the Ref 5 ... as in takes in apart, installs new components and fascia, reassembles it, thoroughly tests it, and then let's Warren Gehl have at it.

My question to you is can you take it? Being without your Ref 5 for a couple of weeks.

Here's my bottom line: the Ref 5 SE (either new or upgraded) is one of a kind. Just do it!!