If you can get a working used/freebie(given) computer of at least 500Mhz or better will be decent enough for them to enjoy small pgms. and/or kid interaction type programming. They will learn the basics and still be able to get internet access with enough speed to be comfortable. Being used, the system will be very cheap if "working" no repairs other than maybe getting to a clean slate as it were. Otherwise, a cheap system and I do mean cheap but affordable are in the $500 range or cheaper if brought on sale, supplied by Compaq, HP, eMachines, Wal-Mart, K-Mart, Best Buy, Circuit City, Fry's and verious online sources. That system is usually an entry system is normally new or a "reburbed" one that's returned to as new condition, just read the fine print. The side benefit of a vendor supplied system is usually some OS and s/w bundle in part of the deal and basic warranty, if new, less warranty if reburbed.