As a UX Designer currently, I would bring in a UI and UX designer as soon as possible. Reason be, if work goes to far, you could be looking at higher expenses to restructure and/or redesign everything to fit the requirements that provides a great user experience for your customers/clients. Understanding the financial resources are limited working in an Agile approach may help to determine the structure of the design work, web / mobile. This way the team can develop within stages (or called in Agile, sprints) to accomplish the project within a timely manner while sticking to the budget. Also, look at developing the web product in a responsive format design to minimize cost.