We will agree to disagree.
Note I did bring funds into the matter, over the years I have been playing and on the forums I have seen numerous players coming in and splashing out on marker, hopper, goggles and fibre cylinders then selling up or complaining about the cost of playing because they can't afford a case of paint, and how dare sites charge over £15 for a case they buy in bulk
The OP has not said any of that but I give my opinion on air for someone starting out
If the OP is flush then there is no worry about splashing out and buying all the gear, I note that he is on the forum with an Etek going for a rotor.
We have not asked where or what style he plays
£ wise a 3000 cylinder always beats a fibre cylinder
£30 over 5 years and disposing is £6 per year
£150 plus 2 tests is £200 over 15 years, or £13 per year
If you don't get 4500 fills then it is just a bigger cylinder, (assuming its not one of the variety of shapes and sizes)
If you get convenient access to fills and never empty the cylinder, or don't carry the paint then the extra space is wasted
There is a difference between 3000 and 4500 capacities, which can be compared with the link below for efficient and air hungry markers
Http://www.scubatoys.com/paintball/paintballshots.asp
A 1.1l 4500 (68ci) at 3000psi on an efficient marker will do over 800 shots
Go up to 4500 and get over 1200 shots
But are you going to be more effective carrying 8 pots as opposed to 5?
I'm not totally dissing fibre cylinders, I currently have 3 active cylinders, normal 68ci 4500, a stubby 4500 and a 13ci 3000. I also have in the cupboard 2 or 3 out of date standard 3000s and numerous out of date co2s of various sizes
I have used all cylinders on most of my markers, including pistol, etek and x7
It's interesting to use a 13ci on an x7 with a 3 inch barrel - not exactly efficient but it shot enough paint and allowed me to carry one pod, be light and mobile
Fibre cylinders do neatly tuck in and roll, as opposed to aluminium / steel flat bottomed cylinders - provided you use it that way
Of the two cheaper second hand cylinders offered out, one has 8 years life with a probable cost of £110 (excluding test postage if required) which is £13.75 per year (more expensive then a new one at £13.33 per year, and it has a damaged regulator)
The other has a similar timeframe but is £10 less so averages £12.50 per year so does work out a little cheaper then new (though fees are to be added for PayPal)
(Though I have not taken into account whether any are branded, have a quicker refresh, an adjustable regulator etc)
The OP may as well buy new, get the full benefit of cylinder life, have a warranty and peace of mind the cylinder has not been battered
If flush then a fibre, if not so flush then 3000psi
It would not be their worst ever purchase