3dsports are a little more vague on it but still going with the pay more hit it further line
Willow is graded by number, from Grade 1 being the most expensive to Grade 5 being the least expensive. The thing to bear in mind is that this grading only reflects the aesthetic appearance of the bat, and not the performance. For this reason, most manufacturers carry out their own internal grading and select bats based on the performance as well as aesthetics. If you’re paying £450.00 for a top of the range bat, you’d be very unhappy if it looked fantastic but didn’t perform very well! This does also mean that some better bats (£300+) may not look amazing aesthetically, but they are graded as such for their high levels of performance.
As you increase the price of the bat, the level of performance expected should also increase, and it’s your job as a customer to decide how much you’re willing to invest against the kind of performance you expect.