Complex sentence: In December 1976, the chrome plated version of the Sovereign cost and the gold plated version, including VAT, but profit margins on the Sovereign were so small that Sinclair ended up selling the Sovereign at a loss, and it was not a commercial success.
Split into simpler sentences: In December 1976, the chrome plated version of the Sovereign cost and the gold plated version, including VAT. Profit margins on the Sovereign were so small that Sinclair ended up selling the Sovereign at a loss, and it was not a commercial success.