While I'm no expert on stats relevant to RE, I'd still love to stats like (everything over time...):
eviction rate
inventory volume
days in market
1b/2b rent
population change
foreclosures
new constructions
house prices
COL change
price to rent ratio
new permits
apts for rent
maybe there is something opensource already?
the biggest obstacle for me to build something like this would be to have an api that gives this data. I doubt there is one api and maybe no apis that cover everything for all cities.
Anyway, getting the data would be the most hardest part for a new product. MLS data usually isn’t open and usually only licensed RE agents can get authorization, and usually only in the area they are operating in. If you really want to disrupt the market, create an open MLS database and somehow sell it to agents that are sometimes contractually obligated to only use a single MLS.
Good luck!