Minimal submissions, what simplest and inexpensive route?

i only really want one form and i anticipate about 30 people will use my form per month to submit a request for me to do something for them.  what is the most economical way to complete this using jot forms? mahalo.

You can set a Submission Limit in the Form Settings. You just need to set the Form Status to "Disable on submission limit" and then specify the number of submissions. Please check this guide for more information: https://www.jotform.com/help/137-How-to-Limit-Submissions-in-a-Form.

Please take note that you need to update the form monthly. For example, you set the limit to 30 and then you received 30 submissions for July. The form will be disabled. It will not enable by itself, you need to manually enable it by deleting the current submissions or increase the limit to 60.

Hope that helps. Thank you.