Some good advice above: +1 to don't get a sniper rifle, or a pistol, and spend your money on extra mags for your rifle. I'll add that your boots and eye & teeth protection should be your first concern.
German Para Boots - currently the cheapest UK supplier. Indestructible waterproof boots that will save you from a broken ankle even if you put a foot down a rabbit hole while running - put insoles in them for comfort and tape the back of your ankles and/or wear Thousand Mile Socks to avoid blisters.
Interlaced Wire Mesh Goggles - this type give the best vision and you'll have no problems with fogging lenses.
These, however, are the best compromise between good vision and protection.
Interlaced Wire Mesh 1/2 Face Mask - also available in other colours from same supplier. This type has a 2nd strap which makes them sit more firmly in place when you run. Bear in mind you may well have to bend it and/or add padding inside to make it very comfortable and, depending on which rifle and how you shoulder it, this kind of tough wire mask can interfere with how your cheek rests on the stock.
Also, IME you should be able to get CS95 trousers and shirt for less than £20 delivered from fleabay.
PLCE webbing is indestructible but may not be so good for a 1st load out, because of the weight, the way it is worn and used, and also because it's so robust that it's sort of awkward at first. Still, it's cheap - currently going for around £20-25 delivered from fleabay, assuming you have the patience to get the best deals. You might be better off with
something like this. That one is Desert Disruptive Pattern Material (DDPM) which are always very cheap;
they also commonly come in DPM, the green, brown, tan, and black camo the British army used to use, which can be had for less than £20 delivered sometimes but, since postage is going up, more like £25; they also come in plain OD or black but those are rare and often expensive...
although
The
South African style Recon Vest is available brand new for less than £40 delivered and, as Tac says, comes in any camo. However there are 2 drawbacks and 2 things to be aware of: 1) the ammo pouches will only fit NATO STANAG mags in them (M4, M16, SA80, etc), no 7.62mm size mags like H&K417 or M14, nor AK, MP5, G36 mags, 2) the pouches are closed only with velcro, they have no press studs or strap & buckle, which means that they are not as secure when tou're crawling about on your belly through undergrowth and, to be aware of, 1) the hydration pouch on the back is actually divided into 2 sections, upper and lower, which is not the right shape for any of the standard 1.5, 2, 2.5, or 3L hydration bladders available - you can fit a 1L bladder in each, but they are more difficult to find and can be quite expensive, or you'll have to modify the inside of the pouch. 2) some of the ammo pouches are on the sides of the larger utility pouches which means that, unless the large pouch is full, mags in those ammo pouches flap about a bit.
While i was having a look for you i noticed
these Croatian Army Assault Vests for £21 delivered:
...which is a decent price for a vest, but also means you'll have something very few others will be wearing.
Oh yeah, and DE make sh!t AEG's, but their shotguns have a reasonable reputation.