Would you willingly provide prices paid to an aggregator to support ongoing price transparency?

Question for folks.

One of my biggest, most persistent frustrations is the lack of price transparency in Portugal. From real estate transactions (list vs paid), to renovation and service provider costs, I think a real problem in Portugal for foreigners (and maybe even locals) is the lack of transparency around prices and costs.

As there are no published prices which aren't geared towards the B2B market, I was thinking of crowd-sourcing information.

The question of course is: are people willing to share this data? It wouldn't need to be address specific, but would need to be at the town or neighborhood level to be of any utility for other folks.

Would you share your sale vs ask price for a property? Cost to do a bathroom reno? etc?

As I say, this is one of the most annoying problems in Portugal and I'd love to find a way to help people get around this.