According to the regulations of the Ministry of Construction and the Ministry of Finance (1999), the collection ratio of the maintenance fund (because the ownership of the maintenance fund has not been transferred, it is not paid but collected) is 2-3% of the purchase price (Hangzhou, Zhejiang can't do this). 2% in most places.

In some places, housing reform is levied at 1%.

The situation you are talking about may be the housing reform, or it may be the developer's promotion method. The developer "sent" a maintenance fund.