Answer:
Yes it is possible to have an increase of 100%.
Retail price is 83.4$
Explanation:
250 = x + (200% of x)
250 = 300% of x
so basically 250$ = 3x
250/3 = 83.3333334
So you can round it to $83.4
Hope this helps. I'm not entirely sure this is true but I hope it is.