Centurion is the bike company. Avenir made the seat or seat cover. Centurion made a lot of bikes in Japan though I believe it was an American company. Earlier ones may have been made in the UK. Yours looks Japanese. I don't know anything about their model line up, but most I have seen are pretty decent bikes. In general I would say this looks like a low-mid-range bike based on the components (mid range), the forged dropouts without adjusters (mid range), and the reflectors, spoke guard, and plastic pedals (low range). In any case at $30CDN it's a great deal.

Cheers,
Karl