What spare kayak parts to keep at home

What are some "reasonable" spare parts to keep at home just in case (so dont have to wait when need something)? Reasonable means somewhat likely to break / wear out within 5 years of normal use OR that are simply low cost (<$10)?

Its a Hobie Revolution with MD180 arc (2018) and I already have spare fins, mast, chain, and idler cable. All ideas are welcome but especially below (do they really break much?)
81123001 IDLER PULLEY GT W/ BEARINGS ... says GT so unclear from Hobie brochure if this fits 180?
81503002 BOOM MD 180 V2

81023001 SPECTRA CONTROL LINE
8004531 LINE (BLK) for RUDDER - UP / DOWN (I dont even know what this is)
81408101 HANDLE (for up down rudder)

81013001 STEERING HANDLE
81016001 REV 13 steering crank (dont even know what this is)

and COSTLY things below
Spine assembly
81611101 CLICK AND GO ASSY

I haven't had any Mirage Drive parts wear out or break on a regular basis. The only part which has broken on my 2014 Mirage drive, which has had a huge amount of use, is one cable. I haven't had any parts break repeatedly. or wear out after a couple of years of use. So it seems to me that you'd be wasting money if you buy a bunch of spare parts, because you'd probably never use them. If a part breaks, buy a replacement. Although it does seem to be a rule of nature that when a part does break, it'll never break at a convenient time, and/or when you're near a Hobie dealer who has a good stock of spare parts. The part will break when you launching on the first day of a multi-day kayak fishing vacation, not as you're coming into the launch site at the end of the vacation.