[ShelledPants]

If you're solo. Spend good money on a green BDU, and then cheap out on your tan BDU, or vice versa. (This is because Green is the dominant color in Canada. You will want to wear it every chance you get)

Teams are often broken down into what color you're wearing and it's useful to have the option to switch or choose your team.

Pistol magazine pouches. (Belt)
Pistol Holster (Belt)
A good belt (HSGI makes some great shooting belts)
Good undergear (T1 wicking layers, Smartwool socks, Sock liners)
A good raincoat, don't get cheap softshells, spend $100 on a decent Goretex jacket from Mec. Don't buy PVC anything, you will cook.
A small assualt backpack. (Ebay, check out USGI surplus backpacks, you can get a 80L Arcteryx Hiking pack and an Assault pack for $120 shipped. And it's Marpat)
Mechanix gloves ($20 a pair) I say this because real oakleys are destroyed in a season of play, fake ones in half that.
Good boots. Don't get zippers, or goretex under $100. They will break and be cold when wet. Canadian MkII's can be found for less than $80 and will probably outlast you. (To agree with eveyone else, good hiking boots are the best right now. I have a hard on for ASOLO Flames. But I currently use Merrel MOABs.)
Wool watch cap. Great in the winter. Good at night in the summer.

Don't throw a flashlight on the pistol. You'll thank me later. It will also save you money.

Co2 Pistols shoot hot. Check your FPS before attempting CQB with it.

Fenix flashlight. Pocket clip. They are great flashlights, $20-$40. Don't weapon mount things you will rarely use. It makes your gun heavy. If you're going to a night game. Tape it to your weapon. 90% of people don't even use their flashlights properly in games.

Clear or Amber lenses in the goggles. You will hate yourself the second you are in a shaded bush. Can't see shit.

You will learn to hate face protection. Make it work for you. Something small and quick to take on and off will mean you're more likely to wear it when you need it (frontal assault).

Personal pet peeve: Armor carriers. Especially new players. Hard to feel your hit. Often you have to hear it. In an intense situation, or even just outdoors, you will likely not feel or hear when hit there.

Camelbak or some other water system. Bottle of water are also fine, but have a place for them full and empty so you don't litter.

I haven't mentioned a RADIO because new players shouldn't be allowed within spitting distance of one.

Dump pouches are a losing game. They are super useful for new shooters. Experienced shooters don't use them. They migrate magazines. Need to drop a magazine fast? Pocket. Then put that magazine back in your rig farthest away from your drawing hand and put your fullest magazine by your drawing hand. Eventually you will be out of ammo and your rig will be full. This is good. Better than to be out of ammo and still have freedom of movement then to have your awkward dump pouch flapping in the wind like a 10lb tumor.

There is my two cents.