Downtime Guild Building

[AsheItachi]

I have a rogue who wants to build a guildhall (thieves) in one of my kingdoms. Shes using a 2 year downtime for the characters as they go from chapter 1 to chapter 2.
I just cant wrap my head around it using the Downtime (http://www.d20pfsrd.com/gamemastering/other-rules/downtime) rules
She has about 4k to work with and 500 days of downtime where do i start and what is the exact costs?

[Oracle_of_Void]

They can either use up 66 Labor and 67 Goods or buy one for 2,660 GP. To find the time requirement, add up the construction time of all the component rooms, all the workstaions and bathrooms and such.