Real estate agents can be helpful but ultimately you are the only one that has to live with the decision long term, so first hand knowledge is invaluable.  

@Michael Morris I'd recommend that you develop tools, books, or some type of download.  

Do you recommend any tools for this such as the BP calculator ?

Get a realtor or lawyer to present the contract and at settlement the lawyer will basically take the check minus the lien (send to the gas company) and the rest goes to the owner --- so if you pay 20k she'll end up with $3000A lien is a legal tool to retrieve money owed to someone so only way it gets removed is to pay it.

It's just the tool that helps owners to protect their investment in a common asset. 

Bay area properties double in value every 10 years religiously.

Dion's service I think would be invaluable to you starting out its very cheap insurance...

Check under the analyze tab above for tools to help you evaluate the deal.

Then, using a tool I developed (Break-Even Calculator - see here for more information) I created the following table.

I have been told that the ratio between the owner occupied units to renter occupied units should not be less than 51%.The property had appreciated in value and I want to pull my money out by mortgaging the investment unit.