The standard lead form that is hosted by Tripleseat is customizable in many ways.
You can make modifications by going to Settings > Lead Forms > Edit Lead form next to the form you would like to modify. On the next page, you will see all of the options that are available to you. If you're looking to add a new field, we recommend customizing the 'Additional Information text' field to fit your needs (for example, Do you have a Budget?) If you do adjust this field, the lead's additional information notes will populate into the "Additional Information" field within the lead itself.
If you require further customizations on your form, your web developer can create one for you by using our API to link it with your Tripleseat site. You will find out API information within our 'Technical Inquiry' section of our Knowledgebase!