This is a guide of what's worth getting from where (e.g. buy that piece with crystals but that one from the shard shop): (
gigantic spreadsheet)
It mostly depends on what gear you need, but generally:
- Wait for things that drop from both Raid boxes to drop
- Buy the gold component pieces with crystals (25 for 375c) - Warning! Not to be mistaken for the salvage, which drop by the dozen from challenges
- Get stun cuffs & carbantis from the guild store
- Get G11 gear, stun guns and some other painful purple things from shard shop
- Farm G11 gear from their nodes