Sell or hold and build?

[Vu Phan]

I have a 20000 sqft property in Southern California which I bought in 2016 for $530k free and clear. There is a small house that being rented out for $1.3k/month. The city let me built 3 SFRs style(can't be sold separately) + additional 2 more ADUs if I choose. A similar property was sold for $840k in 08/21. Should I sell or keep it for development?

Thanks.