If you want a Windows laptop, the current version of the OS needs two processor cores, 4 GB RAM and a minimalist 3D graphics processor (included on most of Intel's mobile CPU chips now). That's to run to operating system. Most applications need very little more resources. Windows XP was fine with about 1/8th the resources needed by Win 7 or 8, so you can't compare specs old to new to find out what is adequate.
Other operating systems are less demanding, thus a Chromebook or Ubuntu laptop can be less expensive. But to meet that price, laptop manufacturers will sell Windows laptops that are inadequate for Windows 7 or 8, and those can be annoyingly sluggish.
