Lots of people have. I nearly went that way but dropped it due to the cost involved and wanting to keep the oem look. I found it cheaper to boost the stock system with subs, speakers, sound deadening and will eventually add amps.
For an aftermarket double din you just need a new facia with the adapter, new lock and airbag lights, the appropriate SOT or ISO adapters, aerial adapter, steering wheel control interface etc....
I have used these guys before..... the link is for a pioneer head unit ....
https://incartec.co.uk/Ford/2535/1036/2072/0That lot will be just under 300. Then you can start adding the head unit and upgrading the speakers etc.