I just put together a REALLY cheap system for budding LVVSA XC pilots
to use. Here's the breakdown:
iPAQ 3870 - ebay $22.50 including shipping (I bought a 'lot' of 5)
New battery - $20.00
Bluetooth GPS from Semsons $23.60 including shipping
http://www.semsons.com/amabg108blgp.html
XCSoar - Free
I haven't determined if I can make OLC valid files yet.