Let's turn this around a bit.
On the Boltek site, list price of the LD-250s are $799, PCI cards are $399.
That's a difference of $400.
For $399 (a buck less), you can get a new Dell Vostro 200 with 1.8 GHz dual core, XP Home, no crapware, 19" wide-screen, 1 GB RAM, 16x DVD-ROM, and 80 GB SATA HD.
Get the Boltek PCI and a new computer and monitor for a buck less than the lesser LD-250 by itself.
Keep your existing PC for the weather station or add a multiport PCI card for your serial for a few more $$, and an Ethernet or USB wireless client if you still need wireless.
(thanks to kray1000 for having my back...)