A man goes into a hardware store an buys something.

1 for $1
12 for $2
112 for $3
What does the man buy?

House (address) or boat(license) numbers, one at a time.

To figure out what the man buys, let's examine the pattern of the pricing.

According to the given information:
- 1 item costs $1.
- 12 items cost $2.
- 112 items cost $3.

If we observe closely, we can notice a pattern. The number of items seems to be increasing exponentially while the price remains constant. Let's break it down:

1 = $1
12 = $2
112 = $3

We can generalize this pattern as follows:
1 item = $1
10^1 + 2 items = $2
10^2 + 2 items = $3

So, following this pattern, for each step, the man adds a power of 10 (10^1, 10^2, etc.) to the number of items and still pays an additional $2.

Now, let's apply this pattern to find the number of items the man buys for $4:
10^3 + 2 items = $4

Therefore, the man buys 1,002 items for $4.