U get what you pay for tbf spend £70+
Have we rewound 5 years again?
Back then the same advice was given - 'Buy the most expensive ______ you can afford', 'unles you buy the most expensive then you have wasted your money as you will buy it later' .... etc
You do get what you pay for, however the requirements for goggles are:
Suitable for paintball
Comfort
Vision
Add to any purchase - affordability. If you buy only the expensive items then the average new player then cannot afford to play.
Paintballers always want the next new item and tend to replace items anyway. Spending £70, £100 or more on goggles is only money well spent if you have tried a few on and know why you are paying the extra £.
Spend £30 now and update later in a few months when you are experienced enough to spend well then you can give away, sell cheaply or keep them spare. Keep them as a spare and the lens will also probably be cheap and worth buying to keep for your occasionaly used spares.
Spend £70+ now on the wrong goggles then you can sell them for about half price or still keep them, but the lens is not so cheap to maintain a fresh spare set of goggles.
£30 goggles are suitable for paintball, and even have anti fog lenses. Take care of the lens and it will remain clear..
If there is space around your mouth then the air can flow. You can pay £70+ for airflow, or you can pay £30 for air flow. It depends on the design and your head. If the goggles fit your head they will be comfortable.
If you have fogging issues then you can deal with that for around £5 on cat crap/zero fog. You have still spent half the price or less compared premium goggles.
Try things on and buy wisely for your pocket.