I second the comments made by Jeff C. The TREC form is very easy to fill out, and it doesn't take very long. The form is necessary because a residential sales offer consists of a lot more components than just a price. Anyone can fill one out the TREC form. You do not need a real estate agent to fill one out for you. I am not a real estate agent, and I have filled them out for residential sales on my own behalf. I am an attorney, but if you understand your rights and obligations under the contract and how contracts work, then you can easily fill one out on your own.
I have negotiated down the seller's agent's commission to 3%. If you ask nicely, many seller's agents will agree to "split" the 6% commission with you. (Technically, the agent cannot split the commission with you unless you are a licensed agent, but they can work the numbers out to where you will get the equivalent of 3% of the sales price in your pocket.)
Do not go around the seller's agent. The seller has retained an agent because he/she does not want to deal with potential buyers, doesn't understand the process and needs professional assistance, or for any number of other reasons, none of which you want to ignore. You do not want to annoy the seller or the seller's agent if you want to get a deal done.
If you don't want to retain a buyer's agent to help you (most I know will want at least 1% to represent you, which may not be cost-effective for you), I can look over your TREC offer after you complete it to help you understand the legal aspects of the contract.