Just some general tips, for a more professional presentation, you will probably want to use a larger frame than the print size and use a nice matte on which you can mount the photo. This gives a nice border between the frame and the photo and can help maintain accurate looking color regardless of viewing environment since people will see it in context of a fixed color background.
Without the matte, the edge of the frame may crop part of the image and the color of the wall on which the frame is mounted will influence the way the colors are perceived more.
You also need to decide if you want to do matte, luster or glossy printing, keeping in mind that if you are going to use a glass frame, then the glass itself is going to be glossy as well.
$30 is certainly a doable cost for making such a print, but it can really vary a lot depending on how nice of a frame you use, how you mount, how nice of a matte you use, how nice of printing you use, etc. Getting a top end 8 by 10 print alone could run you $15 to $20 potentially and it's easy to spend more than $100 just on a frame.
If you want to do some cheaper ones as well, getting some mounts, some 3M spray adhesive and some sheets of foamcore can be a nice, cheap way to make good looking prints that could sell at a lower price (might be a good idea if this is your first attempt at a sale). Black foamcore can work as both the mount and the matte and will hold up well for wall mounting. It is also still thin enough to be placed in a frame if someone so desires. If going for a foamcore mount I highly recommend either luster or glossy printing and possibly lamination. An 8 by 10 foamcore mount (with print) can probably be done for around $15 with moderate quality printing. Probably $10 if you go with cheaper printing (something like Sams Club or Costco quality.)
It really depends on how much you think the print is worth and what kind of cost that justifies spending on the presentation. If you expect the print to go for $50 then spending $30 on production might even be a bit much. If you expect it to go for $300, I'd go a bit more elaborate with the mounting and framing.