Spending money for customer discovery and validation

I am looking to create a solution for training mechanics. I do not own a car (since I also work on public transit). But have been doing a lot of cold outreaches to dealers but it has been slow and difficult to validate any traction. Do you recommend spending $$ to attract discovery interviews through SEM? Is that worth it or not? And if yes, how do you recommend setting this up? Do I just put a landing page together and spend a little bit of money on SEM? If not, how do I do better on validation? What are some best practices?