@Nick Louie @Joe Norman I second what Joe Norman said. I can only speak to representation in Texas, but this is a very typical agreement for Buyer's Representation. Professional Service Compensation with a time period with an expiration date.
I do what Joe mentioned, and let my buyers know should there be a situation where the property/seller is not covering my professional service fee, and then ask what they would like to do. There was discussion on one of the BP podcast episodes about working with an agent vs getting your license that touches on this same concept. The expertise of an experienced buyer's agent working for you, you will likely negotiate more than whatever the professional compensation for your agent is. The truth is, if it is a good deal and the number make sense, everyone will win.
Speaking as an investor and real estate agent, both parties need to be motivated for a successful relationship and transaction. Especially when good agents spend lots of upfront time, energy and expertise locating, networking and negotiating deals for their clients. In Texas, a signed agreement solidifies the fiduciary relationship between agent and client, and in my opinion, both parties are much better served.