Xur has it, 5 packs for 1 coin. Do it. I'm sick of raiding and hearing, "I only have 2 heavy synth, so I'm not going to use one." OR, "I only want to use my heavy synth if we are really close to beating him." You need to all be popping those things as needed, without hesitation. Many runs at Gatekeepers in the past and now Crota have been destroyed by this. Sorry for ranting.