[Beowulf] cost of adding to nodes

[Ajay-Kumar M Tannirkulam]

Hi ,
I am an astronomy grad student at the university of michigan. the dept has 
a beowulf cluster with 16 nodes and the following specs:
model name      : Intel(R) XEON(TM) CPU 2.00GHz
cpu MHz         : 1999.788
cache size      : 512 KB

We are thinking of adding 8 more nodes with atleast 2.0Ghz processors and 
2GB of memory. the switch slots for these nodes are already available.

could i get a rough estimate of the cost per node? Do you know of a we 
site where i could get detailed specs and price info.

Thanks
Ajay