Ebay is the cheapest for short chainring bolts (that i know of).
I bought a set of five anodised ones last week from Tripple Butted Cycling on there for £6 posted. CRC etc seem to ask £10-£15 and when i bought some Middleburn ones a few years ago they were made of cheese and certainly not worth double.
I’ve recently built my first 1×10 and have already upgraded the front ring to a Renthal one as my new XT ring lost the chain on my first hop up a kerb despite using a basic Superstar chian device. SS specific front rings have bigger non ramped teeth which should help keep the chain on better. I hope…..