Long distance MAG strip reading?

Hello everyone,

I'm a long time computer-dork type who's dabbled w/ electronics his
whole life. I've never really built any electronic circuit aside from those
I had directions for, but I have an idea and I just wanted to get a idea of
what direction I should head or avoid.

This whole thing is long, the two questions are at the end. Any help is
greatly appreciated.

Here is the basic idea. I will have a magnetic strip reader (for reading
credit-card type cards). I want to read the card, and send it over a wire
over a long distance -- let's say 200 - 500ft to a PC to be processed by
software. There will be many of these devices, but for the sake of this,
let's say there will be 10 of these readers connected to the same PC.

The goal is to make this as afordable as possible and scalable. Some
setups might have 1-5 of these, others might have 100+ all connecting to 1
or as few PC's a possible. Not expensive PC's, even a 286 would be enough.
The ideal cost of each 'node' or 'module' (credit card and method to sent
the data to the pc) would be $30/ea. But even $100/node would still be a big
savings over the alternatives.

The basic idea is to have these card scanners all connect to 1 PC. I
would love to have the ability to have as many of these connected as
possible Whenever a card is scanned the device just sends the card
information to the PC and that's it, the rest is done on the PC. Seems
simple enough. The two problems are 1) Distance and 2) Having many
connections.

From what I can find, most mag card readers that scan the card and read
the data come in 3 styles: USB, RS-232, and PS/2. Both USB and PS/2 have an
issue over a great distance. PS/2 and RS-232 both have issues with it being
hard (and costly) to have many of these type of connections gets complicated
and costly, as well as limited (~18). USB and PS/2 have issues with limited
abilities to determine which port they are coming from when you have many of
them. I know there are RAW card scanners out there... but I don't know if
that would help me.

So then I thought of other standard PC connections that would work well
with this. Ethernet came to mind. Ethernet is good up to 500-700ft, cheap,
and you can have ALOT of them. So if I could combine an 'ethernet packet
generating device' with one of the card readers (USB, PS/1 or RS-232), I'll
need to create a packet and send it out.

The way my brain works, I'll need some sort of low end CPU to generate
this packet. I know I read about a x86 processor available w/ a programming
language. I figured this might be a good use for it. Each 'module' would
consist of:

1) card reader
2) way to read in the card data
3) x86 processor
4) way to build the packet
5) ethernet-type device

Question 1: I don't know what's out there, and just wanted to see if
anyone might know of a place to start reading up on how feesable this all
would be

Question 2: Is there another way to send a credit card scan over a wire
200-500ft?

Thanks for the help,
Joe Webster