Hey there Peter,
I think you have some unknowns here, and the bottom line is: what discount are you getting, how willing are you to replace/repair parts, and as Pitcher said how handy are you?
I owned a B2 from new for 12 years or so (still have it, no longer in service), and now have an ECM (another E61 machine, very similar). At 8 years, you are definitely into the phase where you will be replacing things and I feel that’s to be expected. As to the lack of descaling, that may or may not be an issue—where I live, I rarely descaled my brewtus and didn’t have any buildup to mention. Definitely not the case in all areas. As an aside, I’ve been using the BWT system (WLL carries it) for maybe 6 years now and it is money well spent. No more descaling is their claim, it’s been true for me (I live in a different area now than I did with the B2 that didn’t scale, harder water here).
If it were me, I’d consider the following parts likely to need replacing relatively soon:
—both boiler elements
—overheat sensors on top of both boilers
—vibe pump if it’s a vibe machine and possibly solenoid/plunger
—miscellaneous copper and silicon tubing, esp the copper tubing to the hot water boiler which is prone to clogging shut
—seals for the E61 group
—vacuum breaker for the steam boiler (this can be repaired with a simple o-ring, instead of buying the whole part from a vendor—I have a bag of 100 high temp/food grade and happy to send you one or more).
—E61 portafilter gasket and screen
Less likely but possible:
—Giemme control box
—over pressure relief valve on the steam boiler
—seals for the wands
So if you add those up, and they are less than the discount you’re getting on the machine vs. new (and you like to work on machines), I’d say go for it! In any case, you will know the machine well, and since you’ll be doing future maintenance on any machine, it’s good knowledge to have. Meanwhile, I’d just get the machine and use it, fix the leak, and then be pleasantly surprised (and money ahead) for the time that you don’t need to do the things I mentioned above. ;)
As to Pitcher’s comment about his machine leaking since new, that is not normal in my experience. I can’t recall a leak in mine ever, unless a line blew or something like that. You should be able to chase that down and fix it, I hope you can too Pitcher! Water under the machine is one of those things that drains my energy fast—just annoys the crap out of me I guess!
One tip/suggestion—Expobar uses a liquid sealant on threads. It works great, but it sets up FAST. You have to be really quick to get things aligned, etc., especially on the pump assembly. I have always used yellow teflon tape instead (you could add teflon paste over the tape if you wish) and have never had a leak that I can recall. Just might save you a little headache/heartburn.
Best and good luck with the decision and/or new machine!