What serial server to buy for UPB?

Over the years and today I have used Quatech, Lantronix and Digi (of old) serial servers to access serial UPB PIMs around the house.
 
Looking to purchase an inexpensive small network serial server these days for same purpose.
 
I am using Upstart and running it in Wintel (VB's these days).  I seen a few on Ebay for around $20 or so.
 
Any recommendations for an under $50 serial ethernet server?

To be honest, I would probably just use a Raspberry Pi with a USB serial dongle and http://www.conserver.com. It's what I use for my serial consoles on my network devices now, I just have a 4-port usb-to-serial cable hanging out of the back of one of my other systems in the network rack (not a Pi). 
 
From my Mac, I just 'brew install conserver', configure it, and then I can run `console <hostname>` for anything I have connected to the console server.

Welcome to the Cocoontech forum drich!
 
Thank you drich.
 
Yes I have done that too just a few months ago because I didn't feel like hanging around the server room and wanted to configure a Cisco router from my cubicle. 
 
Looking for something around the size of an RS-232 interface that I can just velcro to the back of a UPB PIM and use power from the UPB Pim to power up the device or batteries maybe.
 
Thinking I will DIY one using a microrouter / OpenWRT and a tiny USB power supply.  This way I can use it wirelessly or wired and plug it in anywhere. 
 
Googling a bit here see that someone is running conserver on the openwrt router.
 
It would be nice if Upstart ran in Linux.
 
The microrouter pictured should fit fine velcroed on the HAI UPB Pim.