Well,
It's been said before, but opinions are like *insert both gender compatible body part here*, everybody's got one. You will get many responses, recommending many markers, but you ultimately must choose one that's right for you. The cheapest new markers that I can think of are basically limited to spyders and spyder clones. If you plan on upgrading soon anyway, you might want to have a look at the Dragun line. They have markers starting at $89. They're spyder clones with electronic grip frames, they use a 9volt battery, they're cheap, they're fast, and anyone with experience with spyders can work on them. If you're looking for something even cheaper, spyder targas and spyder ones are going for around $40-50 at most online paintball stores these days. They're not pretty, they're not electronic, and they don't have a bottom line.
Of them all, I'd recommend the Dragun, because they're identical in parts and operation to any spyder, and they're fast. But, I must once again refer you to the "opinions are like *both gender compatible body part*; everybody's got one" philosophy