Don't go high caps, regardless of the situation. Mid caps will always be the best option even for REC games. No noise, generally feed better, and no winding. If your going through enough ammunition to warrant using a high cap, (which are generally anywhere between 300-450 bbs) you really need to work on your aiming, or stop spraying. I can easily make a single mid cap last an entire round, and if I do end up shooting a lot, I'll barely tap into the 2nd.
Or you can save even more money and look into used weapons. You can usually find a decent package deal for a very good price.
You will certainly save money going used, but I would suggest a newbie to buy new. You don't want your first airsoft experience to end up half way through a game with a busted gun. Generally speaking airsoft guns aren't super reliable. Getting something used means that you will more than likely have some work to do to it before too long. I can imagine a new player getting a used gun and getting frustrated with the entire hobby because they have to spend time learning how to fix their gun instead of playing. If you can afford $250 in gas mags then buy an AEG instead and buy new.
I agree to an extent. I bought a new gun and dumped a bunch of money into it when I first started. I ended up fielding it twice and now it's for sale. So for less than the price of a new weapon you could get one that has recently had the gearbox gone through, and a tight bore already installed. Not to mention the external extras. It's more of a gamble than buying new but there are good ones out there.