Creation of a new template for FEHAP

The FEHAP would like a community platform with the same functionalities as the ESS : Event Resource Directory Chat Polls

But with a completely different design. The site mockups are in the document "https://drive.google.com/file/d/1phrHtcLxI8-Cugmx9Uv2TAoVSPKmx4Ew/view?usp=sharing" slide 8 to 13

Could you please make a macro estimate of the cost necessary to realize this new template?