On avg £40 return for car on island rates . foot passenger about £6 each way, However I work on island and so mostly travel her, but buy a book of 20 return ar ferry ctickets for £ 400 for all year does us fine for what we want . often go foot passenger anyway .. you can get books of cheaper tickets also if you go regularly .
However depends on what you do , if you work on mainland and travel each dayyou'll need as eaon.. look at wightlink / red jet, just depends on what you are doing..
Check out Rightmove , for island properties and see.