Not for long. Tramiel developed a very bad reputation for screwing over retailers, and his management style led to longer term problems once his family took over Atari Corp. And the terms "platforms" and "compatibility" meant nothing to Commodore in that era. Each machine they built was incompatible with the next, and the C64 was the only truly successful one.
The Pokey had/has its own charm. The SID is nice, but that's hardly what was selling C64s.
Anyways, you're right, pricing. My cousin had an 800XL and I had a VIC-20 and my neighbour a C64. Given a choice, I would have taken the 800XL; its specs were so much better in so many ways and damn that case design was nice. But that product line was always more expensive. If the original 400/800 had been cheaper, Atari would have owned the industry and something like the C64 never would have succeeded. From many points of view it is a superior platform (apart, from as you say, the SID).
According to Wikipedia:
"After losing $563 million in the first nine months of the year, Atari that month announced that prices would rise in January, stating that it "has no intention of participating in these suicidal price wars".[48] The 600XL and 800XL's prices in early 1984 were $50 higher than for the Commodore VIC-20 and 64,[49] and a rumor stated that the company planned to discontinue hardware and only sell software."
Warner Bros axed things and Tramiel picked up the corpse after he was pushed out of Commodore.
I own them all now :-)