Depends on how exactly you define cheap. To be honest with you I can't remember when I have had a pen leak other than fountain pens. Most of the world uses ballpoints or rollerballs now, and even the cheap ones can be quite good.
Basically, any of the following are quite reliable in my experience:
Nicer stuff:
- Cross ballpoints in general. I am quite fond of the broads for those occasions when I must use a ballpoint. Twist action. Probably get you up closer to the $20-30 range.
- the NEW Parker gel ink ballpoint refills. Very smooth and bright colors. Click action. The refills will also fit into Rotrings and a many other brands. Should be able to find a couple of different models of Parkers at Walmart/Target for under $10
Cheaper stuff:
- Pilot G2/Dr Grip - gell ink, but fairly dry comparied to some. Good colors and very close to permanent, so good for check and such. If you leave the tip out they will wet your shirt, but I have never had one leak on its own. Click action.
- Sanford Gel Impacts are the favorites of all the powers-that-be here for signing checks, documents, contracts, etc. They are very wet writers; more like a fountain pen than a normal rollerball. The retractable models have a safety clip that retracts the point when you clip the pen into your pocket. They do not stand heat well though, and can dry up if left unused for a while. Capped or click action.
Cheaper still:
- Zebra tapli - again very broad point, smooth writing, a little gooey sometimes at the start of a line but never had one actually leak. Click action.
- Sanford/Papermate Liquid Expresso pens- huge tanks of liquid ink (visible so you can see how much ink you have left), 'felt' tips available in either a very fine or a rather broad point, nice writing pens with good colors of ink. Capped.
- Pilot Precise Deluxe - liquid ink, not as much capacity of the Expressos, but a little cheaper and smaller. The broad points are super slick writer. Decent range of colors. Capped.