Sometimes, I'm untying my sweats to go to the bathroom and it gets a little dicey.
When upgrading weapons, the Spark Dust (green quality mat) seems to be far more limiting than the Spark Shards (blue quality mat), which seems backwards.
Maybe a solution would be for higher quality weapons to drop both Dust and Shards when they're disenchanted.
And as for the Spark Crystals (purple quality mat), so far I've only gotten two from I think non-repeatable content. And the mat you get from disenchanting purple weapons is some other things entirely that I'm not sure what it's for!