im a casual player and I find it hard when it comes to sell what you dont need to buy and hope geting someting good, what do you sell and what is worth to keep?
I only sell XP - I have a thing about having lots of reqs (Even if I barely ever use them).
I will give you my method and you can decide how you want to handle it from there. I only keep 3 of everything except mythics. Makes it very easy to see what to sell. If I have 4 of something I sell one if I have 2 of something I let it get back to 3. Basically set yourself a limit to how many Cards you want per REQ and if one exceeds that limit sell them
I sell all:
- Boltshots (standard) - Brute Plasma Rifles (standard and Sorrow of Teash) - Carbines (standard) - Energy Swords (standard and Ravening Sliver) - Gravity Hammers (standard and Corpsemaker) - Needlers (standard) - Plasma Pistols (standard) - Plasma Turrets - SAWs (standard) - Scattershots (standard) - Shotguns (standard and Lawgiver) - Splinter Turrets - Storm Rifles (standard) - Suppressors (standard) - Chaingun Turrets (standard) - Gungooses (standard and Corp) - Mongooses (all) - Chaingun Warthogs (standard and Corp) - All Gambit boostsI keep pretty much everything else, occasionally selling a couple to get enough RP for a Gold pack if I have 9000 or so points.
I sell everything that isn’t a: Scorpion Tank, Mantis, Phaeton, Banshee, Wasp, ONI Warthog, Spartan Laser, Beam Rifle, Binary Rifle, or a non-gambit boost. I have all of my other commendations completed, so I keep x1 of every REQ in the game for the sole purpose of saying ‘I got one of those.’
> 2535437652903765;4:
> I sell all:
>
> - Boltshots (standard)
> - Brute Plasma Rifles (standard and Sorrow of Teash)
> - Carbines (standard)
> - Energy Swords (standard and Ravening Sliver)
> - Gravity Hammers (standard and Corpsemaker)
> - Needlers (standard)
> - Plasma Pistols (standard)
> - Plasma Turrets
> - SAWs (standard)
> - Scattershots (standard)
> - Shotguns (standard and Lawgiver)
> - Splinter Turrets
> - Storm Rifles (standard)
> - Suppressors (standard)
> - Chaingun Turrets (standard)
> - Gungooses (standard and Corp)
> - Mongooses (all)
> - Chaingun Warthogs (standard and Corp)
> - All Gambit boosts
> I keep pretty much everything else, occasionally selling a couple to get enough RP for a Gold pack if I have 9000 or so points.
You might wanna hold onto those plasma pistols, there really good if you see an air vehicle PvP or PvE.
> 2533274847563380;6:
> > 2535437652903765;4:
> > I sell all:
> >
> > - Boltshots (standard)
> > - Brute Plasma Rifles (standard and Sorrow of Teash)
> > - Carbines (standard)
> > - Energy Swords (standard and Ravening Sliver)
> > - Gravity Hammers (standard and Corpsemaker)
> > - Needlers (standard)
> > - Plasma Pistols (standard)
> > - Plasma Turrets
> > - SAWs (standard)
> > - Scattershots (standard)
> > - Shotguns (standard and Lawgiver)
> > - Splinter Turrets
> > - Storm Rifles (standard)
> > - Suppressors (standard)
> > - Chaingun Turrets (standard)
> > - Gungooses (standard and Corp)
> > - Mongooses (all)
> > - Chaingun Warthogs (standard and Corp)
> > - All Gambit boosts
> > I keep pretty much everything else, occasionally selling a couple to get enough RP for a Gold pack if I have 9000 or so points.
>
>
> You might wanna hold onto those plasma pistols, there really good if you see an air vehicle PvP or PvE.
I keep all of my Spitfires and Void’s Tears. I figure I have enough of those.
> 2535437652903765;7:
> > 2533274847563380;6:
> > > 2535437652903765;4:
> > > I sell all:
> > >
> > > - Boltshots (standard)
> > > - Brute Plasma Rifles (standard and Sorrow of Teash)
> > > - Carbines (standard)
> > > - Energy Swords (standard and Ravening Sliver)
> > > - Gravity Hammers (standard and Corpsemaker)
> > > - Needlers (standard)
> > > - Plasma Pistols (standard)
> > > - Plasma Turrets
> > > - SAWs (standard)
> > > - Scattershots (standard)
> > > - Shotguns (standard and Lawgiver)
> > > - Splinter Turrets
> > > - Storm Rifles (standard)
> > > - Suppressors (standard)
> > > - Chaingun Turrets (standard)
> > > - Gungooses (standard and Corp)
> > > - Mongooses (all)
> > > - Chaingun Warthogs (standard and Corp)
> > > - All Gambit boosts
> > > I keep pretty much everything else, occasionally selling a couple to get enough RP for a Gold pack if I have 9000 or so points.
> >
> >
> > You might wanna hold onto those plasma pistols, there really good if you see an air vehicle PvP or PvE.
>
>
> I keep all of my Spitfires and Void’s Tears. I figure I have enough of those.
Yea, there better anyways.
I keep 5 of every weapon minus the turrets, and I keep every vehicle other than Mongeese.
I don’t really sell anything except if I’m close to 10K so I can get a gold pack. I’d say to go through your REQ’s and sell the items that you don’t use which will usually be the ones that have a lot of them, but keep some just in case.
Sell what you don’t use. I keep everything even tho I don’t use some of them. I just like to have a stockpile. Just in case I decide to go rampant and do a mongoose only game or something 
Vehicles: I sell all covenant purples, and all unsc paper and corporate vehicles, and all mongoose types. Everything else I keep a stock of 10 to 30 depending on vehicle type.
Weapons: I sell bolt shots, and all base level weapons that have a superior version at the same REQ level, like the hydra, needler, and beam rifle.
Don’t underestimate certain garbage weapons and vehicles though, that have a very strong use in warzone assault. I.e. i always keep a small stock of chainguns, gungooses, and scout hogs for those occasions when i only have 6 or less Spartans in my fireteam.
I sell the gun gooses because they are bad vehicles.
Mongooses. Worthless IMO.