There are 7 Player houses to buy in Forza Horizon 5, and together they are still cheaper than buying a Castle in Forza Horizon 4! You need 7,850,000 Credits (if you have VIP and Welcome Pack) OR 10,050,000 Credits (without VIP & WP)
1st House - Casa Bella - Free - This house is the first house you will come across when you start FH5, and is free! So cannot complain there.
2nd House - La Casa Solariega - 1.5 Million Credits (or Free with VIP) - This house is free if you have the VIP membership for FH5. You can locate this house near the ancient ruins of Teotihuacán. This house will appear on the map after being gifted Casa Bella.
3rd House - Lugar Transquilo - 700K Credits (or Free with Welcome Pack) - Another house which is free if you have the Welcome Pack for FH5. This house is located on the East Coast by the town called Playa Azul. This house will appear on the map after being gifted Casa Bella.
4th House - Buena Esperanza - 700K Credits - This house unlocks on map once you have completed Horizon Apex Expedition.
5th House - La Cabaña - 150K Credits - This house unlocks on map once you have completed Horizon Baja Expedition.
6th House - Buenas Vistas - 2.0 Million Credits - This house unlocks on map once you have completed Horizon Wilds Expedition. [Edit] Perk of this house is it allows you to Fast Travel to any road on map. The more Fast Travel Boards you destroy, the cheaper your next Fast travel will be (minus 200 credits every time you hit a board). Once you've hit all 50, like FH4, Fast Travel will be free.
7th House - Hotel Castillo - 5.0 Million Credits - This house unlocks on map once you have completed Horizon Street Scene Expedition. One massive perk of purchasing this house compared to the others, is you get a daily wheelspin every time you log into FH5. (shame it couldn't be a super wheelspin...)