Originally Posted by cyclotoine
SN on the seattube near the bottom: B5583105, seller said they bough it new in 82 for 500 he described the colour as champagne, Looking at it again I would have to agree with that description as opposed to gold, I actually like the colour and if it was my size I might keep it.
Definitely not an Italian serial number. Unfortunately, I haven't enough data to decode the Japanese manufacturer(s)' serial number code. You can assume 1982 based on the seller's memory, or start investigating the date codes on the Shimano drivetrain. The price sounds about correct, assuming the age and $CDN. Yes, Bianchi literature usually referred to this color as champagne. It was usually paired with blue decals.
The 1980s, Japanese Bianchi were well manufactured, but I do not know who built the frames. I know the unbranded tubing on the 1983 and 1984 versions was Ishiwata, so your 1982 may be the same. Typically, the frame construction quality on a vintage Japanese bicycle is more consistent than an equivalent European bicycle of the same level and era. Regardless, if it's a Bianchi, an Italian frame will have the edge from a collectibility standpoint, particularly if it's celeste.