Check out eBay. I bought a used card on eBay for $15 plus shipping.

for a sound card just for linux, you dont need anything fancy or
expensive , you can get one cheep like 10.00 at a computer store, that
should be ok for ubuntu. i am using one of the ten dollar cards here and
it works great.

I would suggest that you look at Nvidia which is better supported than ATI,
although AMD is slowly coming around.

How do you know that your card is not supported? If it isn't working properly
that could be for one of many reasons including the wrong driver, or monitor. If
it is from Nvidia or ATI you can build a driver with Envy by downloading the
right one from Nvidia or ATI source code and compiling it for your kernel in one
step. See:
www.maximumpc.com/.../easy_graphics_drivers_get_a_green_light_with_en\
vy

What is your graphics card, BTW? What happens when you click on System |
Administration | Hardware drivers?

My video card is a NVidia GeForce 4 AGP card. I know that it is not
supported because the install program told me so early on.

It works just fine with 8.04. If I can't get it to work satisfactorily
with 8.10 I may try the compiling trick you pointed out to me.

What are your motherboard's capabilities? In other words, are you
limited to PCI or is there an AGP or PCIe-16 slot?

This looks helpful, too:

<http://ubuntuguide.org/wiki/Ubuntu:Intrepid#Graphics_cards_and_displays>

I have both PCI slots and an AGP slot. My video card is an NVidia
GeForce4 AGP card.

there appears to be some good info for
8.10 and NVIDIA drivers in this document:

<thadlabs.com/FILES/Ubuntu_8.10_Guide.pdf> [173 KB]

which is still a work in progress.

Some EnvyNG examples are in this
document:

<thadlabs.com/FILES/Ubuntu_8.04_Guide.pdf> [343 KB]

It turns out that all my angst was for nothing. I just completed
installing 8.10 and had no problems whatsoever, even with the video.

I did attempt to use apt-p2p but after 36 hours and numerous restarts I
gave up and went back to the traditional upgrade. I didn't have to
re-download any of the package files with either apt-p2p or the regular
upgrade. Both picked up where the download had ended and went on from
there.