8 or 16 serial board

[Vu Pham]

I am looking for a 8x or 16x serial rs-232 board,  doesn't matter via
USB, PCI or PCI-x.

My purpose is to use it to remotely control the network equipments
( routers, switches ... ).

Is there any advantage of those above boards to the Cisco 2511 ( access
server with 16 serial connectors ) ? eBay has some 2511 for less than
$200, and the 16x serial board is about $600 or more.

Thanks,

Vu