I paid $550 about a year ago for the largest tube they sell (either 13 or 14") and an 'upgraded' diffuser lens.
Solar attic fan about 2 years ago was approx $450.
Can't speak to current prices and permit costs and discounts but this will give you a ballpark.
Smaller tubes (10" I believe) will cost less...maybe $100 less???
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Maryland (DC Suburbs) - first 51 years 
The Villages - next 51 years
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