The Sonex-180 Deluxe was already coming up for a couple of years old when this advertising sheet was produced, but it was one of Gibson's most successful guitars of the period, and very competitively priced too, as the title declares. It was most likely printed in time for the 1982 Atlanta NAMM show.
In the middle of 1982 (1st June), the US list price for the Sonex-180 deluxe (in Ebony semi gloss finish, as shown here) was just $349 - considerably lower than any other model in the Gibson line. Certainly "rock bottom". Candy Apple Red finish was $50 extra, Silverburst and Antique Fireburst $85 extra - but the next lowest price Gibson was "The SG Deluxe" at $599.
$100
$1395
$880
£895
£795