Reddit mentions of 608ZZ 8 x 22 x 7 mm Deep Groove Ball Bearing, 10 Pcs Double Metal Shielded, Fit for Skateboard Bearings, 3D Printer RepRap Wheel, Longboard, Roller Skates, Inline Skates, Scooters etc. (Pack of 10)

I'm pretty new to this too, I bought my Ender 3 Pro around the same time as you. Quiet printing is pretty high on my list as well as being able to print high-temp exotic filaments in the long term while maintaining reliability.

First upgrades I purchased were stiffer bed springs so I would be less likely to throw the bed out of level while removing prints or working around the printer and Capricorn XS tube since it has a more consistent internal diameter, fits closer to the filament, and can work with slightly higher temps. I also picked up a pack of bowden couplers recently as I noticed the end nearest the extruder is sliding past the coupler jaws on de/retraction; don't worry about that unless it's an issue for you. That's about $30 alone since I don't have a supply shop locally and have to order those parts in bulk. I had a Pi 3B laying around unused and flashed Octoprint onto it. Highly recommended. I have a replacement Noctua hotend fan, buck converters, and 5015 blower on order to quiet the fan noise; about $32. Just replaced the Meanwell psu fan with a 60x25mm Noctua I had lying around (Note: there may be better options in the 92-120mm range to replace part of the PSU housing, but that's what I had laying around). Next upgrade coming is the SKR Mini E3 with TMC 2209 drivers ($28) to eliminate almost all of the stepper noise. Also looking into a replacement for the control board fan and some vibration isolating feet for the frame. As far as higher temp printing I haven't made a lot of progress aside from buying a titanium all-metal heat brake ($11) winch I have yet to install or inspect, and looking into enclosure and electronics relocation avenues.

Either way the mods I purchased came in at around $100 US which should quiet the printer and help with reliability. Also looking into picking up a good M3-M4 bolt kit if any exist in the US.

Here are some links to the things I picked up and will, which may be helpful if you're in the US. Mostly from Amazon.

Type | Name | Link | Price
---|---|----|----
Reliability | 8mm x 20mm yellow springs | Link | $6.98
Reliability | Capricorn XS Tubing | Link | $11.49
Reliability | PC4-M6 / PC4-M10 Pneumatic Bowden Fittings | Link | $11.99
Silence | Noctua 40mm x 10mm 3-pin fan | Link | $13.95
Silence/Various | LM2596 Adjustable Buck Converters | Link | $10.95
Silence | 24v 5015 Radial Ball Bearing Fans | Link | $7.19
Silence/Various | SKR Mini E3 w/ TMC 2209 drivers | Link | $28.81
High Temp | Titanium All-Metal Heat Brake | Link | $11.52
TOTAL: $102.88 US + Tax

Parts already purchased/ bought with printer

Type | Name | Link | Price
---|---|----|----
Reliability/High Temp | OEM Ender 3 Glass Bed | Link | $20
Reliability | Feeler Guage Set | Link | $5
Reliability | 608zz Bearings, using with this(My Remix), this, and this, though I like this design a bit better | Link | $5.98
QoL Improvement | Raspberry Pi 3B w/ Octoprint | Link | $34.46
Silence | Noctua 60mm x 25mm 3-pin fan, goes with this mod | Link | $14.95
TOTAL: $80.39 US + Tax

Future planned upgrades

• Bl Touch (Note: if you have a Pi you don't need a separate ISP to flash a bootloader to the stock Melzi control board)
  
  
• Extruder | Zesty Nimble, Bondtech BMG, or SeeMeCNC EZR
  
  
• Cooling Duct | Either Smooth Fang or Hero Me Gen 3 in PETG/ABS
  
  
• Direct Drive | Kit or Printed (this, this, or this)
  
  
• Electronics relocation enclosure and wiring (need to research this more)
  
  
• Vibration Isolation Feet with Yellow Dot Squash Balls
  
  
• Linear rails (maybe)