Have you looked at the embroidery only machines? The Janome 300E is an older model that you can get for around $900 or less. It uses older technology PCMCIA card with compact flash for embroidery transfers. You can find the pcmcia cards and compact flash on ebay all the time. I've had my Janome300E for 7 years now using the same set when I bought it. They have a step up from that one the 350E and I think it uses USB and that machine is around $1200 new. I use my embroidery machine all the time and have only had repaired once. The repair was replacing the needle threader.
www.kenssewingcenter.com (i think the link is right) will take payments and give you trade in. They are in Muscle Shoals Alabama. I am not associated with them just one very happy customer. He also sells on ebay with seller name easyterms.
A lot of people have been getting the Brother PE770 embroidery machine and love it too.
If I were in your situation I would cut my losses on the Viking, see if you can use it for some trade in value, and get an embroidery only machine. With a 500.00 repair bill that same money can put you over half way to purchasing a new machine.