WORK IN PROGRESS
This is an oft asked question. And it is oft answered as well. Rather poorly, I might add.
What is a good beginner gun?
The answer?
There is no such thing.
Due to a combination of circumstances, including boneheaded players, boneheaded manufacturers, and some relatively recent low cost markers, there is no “good beginner gun”.
You can only separate guns roughly into two categories: good guns and shitty guns. (Or maybe “cheap guns and expensive guns”.)
Criteria: Price
As of recent years, good paintball guns have been targeted at the lower priced segment of paintball. Small, light, efficient electros used to easily cost $800+, but since the advent of the SP Ion, a good electro can easily be had for ~$300 new.
The best example of the lower range of performance and value is nearly anything made by Tippmann. This includes the ‘98, the A5, the X7 Phenom, and even the TPX.
All of Tippmann’s products are made to be as cheap as possible. This is why they’re made out of pot metal and have generally poor manufacturing results like overspray and lack of finish on parts. The top of the line is the X7 Phenom, which runs $400, although that does include a hopper. But even dropping $400 on a Tippmann still doesn't get you a particularly competitive marker. I mean, the thing doesn't even have eyes. And don't give me any shit about the Cyclone.
On the other hand, an Invert Mini, which is a perfectly good gun, comes in at $325 new. Or something like a Proto Rail for $240.
The flipside of this is that you need to have two other pieces of equipment to feed such a high performance gun: an HPA tank (prices have come down on those, but still far more expensive than a CO2 tank), and a hopper. Ironicallly, as fast guns have gone down in price, comparably fast hoppers have actually gone UP in price -- to the point where arguably the best hopper -- the Dye Rotor -- costs nearly $200. A Prophecy Z2 will run $170 new.
Criteria: Upgradeability
You want a gun that might start out as a beginner gun, but can be upgraded to a high level marker. Currently, no such gun exists. If you start out with a Tippmann 98, then the best you will get out of that will still be a Tippmann 98. It's not like you can upgrade a '98 all the way to an Empire Axe or PE Ego.
The closest we ever came to this was going from a Spyder to a classic Intimidator, but that was really because the original Intimidators were just expensive dressed up Spyders with pneumatic rams and 3-ways instead of hammer springs.
Most "upgrades" for paintball guns then simultaneous waste your money while not actually making your gun any better. In fact, sometimes they're worse than the stock parts. This has gotten a little better over the years with the economic culling of manufacturers, but so long as demand for worthless parts by worthless players exists, there will still be shit parts.
The myth of the “backup marker”
Some people say that they can relegate the beginner marker to their “backup marker”, when really what they’re doing is making a shitty justification for marker whoring.
The purpose of a backup marker is to keep you in operation as much as possible.
Why then would you have a marker that was DIFFERENT than your primary? So you can carry twice the amount of specialized parts kits?
If your intent is maximum uptime, then your backup marker should be of the same type as your primary. It should share functional parts with your primary.
If the first gun goes down, you go to the backup.
If the backup goes down, you at least have a chance to Frankenstein a third working marker with parts from both guns.
If nothing else, at least you only have to carry spares for one type of gun, not two.
This is the kind of stupid, illogical shit that runs rampant in our sport.
Bottom Line
Beginners should not be buying paintball guns. Their focus should be on learning how to play better so that they become intermediate players as quickly as possible. This is independent of whatever gun they are using. Once they become intermediate players, the question is moot.
The most practical advice: start out with protective equipment like mask and knee pads. Good masks can be had quite affordably and are well worth the money. The importance of protective equipment is nearly on par with the paintball marker. After all, you can’t hit what you can’t see. Usually.
Continue to rent or borrow until you are sure you really want to get into paintball, and then go for the gun you really want, instead of wasting money on some shitty “starter” gun. By that time, you should be smart enough to know that a paintball gun doesn’t have to cost $1000 to be effective on the field, and you will have saved a lot of money by not upgrading a pile of shit.
Also, do your homework and learn your equipment, and you should be able to buy your guns used at a significant discount.
