Conversation so far:
where was the first silicon photovoltaic cell developed
Photovoltaic technology is born in the United States in 1954 when Daryl Chapin, Calvin Fuller, and Gerald Pearson develop the silicon photovoltaic cell at Bell Lab.
what was the cost per watt of photovoltaic cells back in the 50s
A one-watt cell cost almost $300 per watt in 1956 while a commercial power plant cost 50 cents a watt to build at that time.
did the prices of the photovoltaic cell come down
in 2015 photovoltaic solar cell prices went down by a factor of 100 over the last 38 years; and down by a factor of 25 over the last 15 years.

Question: how much was the price then
Self-contained rewrite: How much was the price of the photovoltaic cell in 2015