The world's first laptop or 'portable' computer - the Osborne 1 - was marketed in 1981 for $2,000:
It's spec was:
* Dual 5¼-inch, single-sided 40 track floppy disk drives ("dual density" upgrade available)
* 4 MHz Z80 CPU
* 65 kilobytes main memory
* Fold-down keyboard doubling as the computer case's lid
* 5-inch, 52 character × 24 line monochrome CRT display
* IEEE-488 port configurable as a Parallel printer port
* RS-232 compatible 1200 or 300 baud Serial port for use with external modems or serial printers
It was powered by a wall plug, and had no internal battery, although a battery pack offering 1 hour run-time was available.
http://en.wikipedia.org/wiki/Osborne_1