The water gun is worth 99.99M credits.

the exchange rate for 1 credit is 100 bits.
100 x 99,999,999 = 9.99B (9,999,999,900 bits)
and for example, you make 100 bits daily (100 bits / day)
$9,999,999,900 ÷ $100 = 99,999,999 days

Now let’s see how many years that is:
99,999,999 days ÷ 365 = 273,972.6 years

So to purchase ONE Water gun with the daily reward (And no premium ranks)
It would take you about 274,000 years, 7 months, and about 6 days to reach that amount at $100/day.