Ok as I have negotiated a couple sponsorship agreements with GM and I have a little knowledge of how they work.
Equipment only sponsorship is for young upcoming players who are on the rise. Usually 2 year deals that GM will supply equipment usually 4 times within the 2 years. GM is the hardest to secure a sponsorship deal from, they supply usually 5 bats, 6 pairs of gloves, 2 huge bags, 3 pairs of pads, 3 full sets of clothing, 3 thigh pads and inner thigh pads and 3 cricket boxes, 2 helmets and 2 t0 3 pairs of shoes but most sponsored guys have deals with Asics.
Any breakages of bats are simply replace but often these guys break their favorite bat so they will refurb and GM will supply a new bat at the same time. When new models are released 5 new bats are sent and old models are restickered and sent back, GM will request that old models are used as net bats. What many sponsored guys do is sell on old models for pocket money.
Sponsorship with endorsement. Ricky Ponting receives $650,000 USD as an endorsement from Kookaburra to use their brand. Ponting used to have his own batmaker make his bat and have the bats stickered up. But this became well known it was rumored that Kook forced him to use the bats coming out of SG and he was none to impressed apparently. Ricky Ponting along with Mike Hussey are bat nerds so very fussy about their bats it is rumored that Ponting will not allow anyone near his kit and Hussey always has a set of electronic scales with him so all bats can be weighed and reweighed.
Shane Watson requests that his bats are big, balanced, pick up and ping he bats at a weight of 2.10 and does not request high grain counts. It is rumored his deal from GM is around $500,000 USD.