Omega View and Toyo View cameras were made by the same company, and a couple of their cameras were sold with both labels. The C was one of them. That's related to your camera because most of the Omega & Toyo accessories and parts are interchangeable -- often between different models, like lens boards.
That being said, the ASKING prices for Omega View and Toyo View cameras on EBAY are all over the place. Fortunately for you, EBAY allows you to search for SOLD items. That's what you should look at, but those SALES prices will vary too. Much has to do with whether you have a good description and good photos -- and your camera's condition, and accessories.
The model C was the economy model in the 1990's, but the selling price at the NY warehouses was about $1,000. The top GII model at that time was selling for $2500, new.
Some sellers think that they can get as much as they paid for their camera -- thanks to inflation. You'll find out when you look on EBAY.
If your local camera shop offered you $100, that means they think they can sell it for at least $200, and up to $400. Compare that to EBAY SALES.