I agree and in fact I know about at least one client who's using a pages database for this.
Pages is perfect for this since a real estate database doesn't require that many additional features ( which you can always add as a custom app, which is also much easier to maintain compared to a stand alone app which would need to be updated after BC breaking changes in IPS)
Categories would be the types and then create custom fields for location , size, price, status, upload field for pictures, etc..