Client says they "don't sign contracts" - should I walk away?

I publish illustrative scenarios prepared by my practice. All participants and conversations are fictional. The fictional posts are not posts by real users, accounts of client experiences, or reports of actual results.
Illustrative scenario prepared by my practice.
For informational purposes only. Not legal advice.
Hypothetical question

Sorry for the wall of text. Potential $15K project. Sent my standard services agreement. Client responded "we don't sign contracts, we just work on trust." Should I run or is this common?

Illustrative response

Ok so update: They signed the simplified agreement. Turns out they were just intimidated by the 8-page original. 50% deposit arrived today. Crisis averted smh!