Define a specific instance of the Traveling Salesman Problem (TSP) with 10 nodes and specific weighted edges. Explain how you would formulate this problem as an oracle for Grover's Algorithm to find the shortest path. Describe the structure of the oracle function that marks the correct state, calculate the theoretical number of iterations required for amplitude amplification, and discuss the limitations of current NISQ (Noisy Intermediate-Scale Quantum) hardware in implementing this solution compared to classical brute-force methods.