Dealing with measure groups of different granularity
If you want to see measures from two different fact tables side by side but different granularity, it's possible but not perfect. For example, the measure for purchase amount in FactPurchase has no monthly equivalent.  

To do this, it helps to have as many related dimensions between both fact tables. So if you have a dimension such as property type that is related to FactPurchase, I would make that a dimension on FactMonthlyStatus as well. This can be done by adding these to the actual FactMonthlyStatus table and figuring them out in your ETL process or by creating a view that sits on top of FactMonthlyStatus that does a join to lookup these dimensions as they are loaded into your cube. However, you are still going to have dimensions such as month that are at a lower level of granularity than FactPurchase. 

The main thing to figure out is how your measures in both fact tables relate to each other. Are you attempting to keep a running total for rent paid and see how it relates to what you paid for the property? If that's the case, it might make sense to create a cube based off a single view that combined the FactPurchase with an aggregate of FactMonthlyStatus to see how they compare.