Just picked up an ender 3 for £139.99 black friday deal from a competitor. Technically my christmas present so may have to wait until i can build it and play.
Any essential upgrades worth buying now and installing while building? already ordered some motor dampners.
Many of the most useful upgrades you can just print.
However, off the top of my head:
Spares useful to have:
Spare nozzles
Spare PTFE tubing
4010 24v fans, my original broke and then one replacement broke. Good to have in stock and cheap.
Stuff you might want to replace pretty soon, also spares of:
Couplers for the tubing - the stock ones are pretty pony and quite likely to give you trouble as they don't tend to grip very well
Heatsinks for the steppers after you install dampers - not positive these are needed but the motors did get significantly hotter once the dampers were installed so I put some on (40mm square x 2)
235 x 235 glass or mirror - IF your Ender doesn't come with the jazzy build surface, I think they all do now?
Spare
Stuff you probably will want for your prints and upgrades
5015 blower fan (24v) if you print a Petsfang cooler. You can print the Bullseye version of the Petsfang though and use the stock blower, supposed to be good still but I haven't tried it.
Mixed m3/m4/m5 hex head screws, needed for some upgrades
m4/m5 t-slot nuts
608z bearings are used for a few upgrades
What I will say though is probably best to build it stock and then fit upgrades as and when - to rule out your upgrades being the cause of problems.