Sure, I can help you write a test case generator for the "Quest of Merchant" problem. To get started, let's outline the input and what needs to be generated:

### Problem Statement: Quest of Merchant

**Parameters:**
1. \( N \) - Number of towns.
2. \( M \) - Number of different products.
3. \( W \) - Maximum weight Rabbit can carry.
4. \( T \) - Total time Rabbit can spend.

**Town Information:**
- Each town \( i \) has:
  - \( L_i \) - Number of different products sold in the town.
  - \( X_i \) - X-coordinate of the town.
  - \( Y_i \) - Y-coordinate of the town.

**Product Information:**
- Each product \( j \) has:
  - \( S_j \) - Name of the product.
  - \( V_j \) - Weight per unit of the product.
  - \( P_j \) - Selling price per unit of the product.

**Product Prices in Towns:**
- For each town \( i \), product prices:
  - \( R_{i,k} \) - Name of the product.
  - \( Q_{i,k} \) - Price of the product in town \( i \).

### Test Case Generator

Here is a Python function to generate random test cases for this problem:

```python
import random
import string

def generate_random_name(length=5):
    return ''.join(random.choices(string.ascii_uppercase, k=length))

def tcgen():
    # Generate random values for N, M, W, T
    N = random.randint(1, 100)  # Number of towns
    M = random.randint(1, 50)   # Number of products
    W = random.randint(1, 1000) # Maximum weight Rabbit can carry
    T = random.randint(1, 1000) # Total time Rabbit can spend

    # Generate product information
    products = []
    for _ in range(M):
        S = generate_random_name()
        V = random.randint(1, 100)
        P = random.randint(1, 1000)
        products.append((S, V, P))

    # Generate town information
    towns = []
    for _ in range(N):
        L = random.randint(1, M)  # Max number of products in a town should not exceed M
        X = random.randint(-100, 100)
        Y = random.randint(-100, 100)
        product_prices = []
        for _ in range(L):
            R = random.choice(products)[0]
            Q = random.randint(1, 1000)
            product_prices.append((R, Q))
        towns.append((L, X, Y, product_prices))

    # Print the test case
    print(N, M, W, T)
    for S, V, P in products:
        print(S, V, P)
    for L, X, Y, product_prices in towns:
        print(L, X, Y)
        for R, Q in product_prices:
            print(R, Q)

# Example usage
tcgen()
```

### Explanation:
1. **`generate_random_name` function:** Generates random names for products of a specified length (default is 5).
2. **`tcgen` function:** 
   - Randomly generates the number of towns (`N`), number of products (`M`), maximum weight (`W`), and total time (`T`).
   - Generates product information which includes a random name, weight, and selling price.
   - Generates town information which includes coordinates and the list of product prices in each town.
   - Prints the generated test case in the required format.

You can run the `tcgen()` function to generate and print a random test case for the "Quest of Merchant" problem. Adjust the ranges and limits as necessary to ensure the generated test cases are within the problem constraints.