Here in the UK prices are collapsing. Plenty of new TFT screened units at around the 630 GBP mark plus local taxes. Very capable machines unless you are working in an extremely specialised area.
Wise council above from SLF. Batteries (Nicad), Screens, tubes illuminating them and type/brand specific memory makes repair and upgrading a very tricky and expensive proposition.
There's a war out there in the PC world as markets slump. True bargains abound - they're brand new and guaranteed.