I know this can very widely and depending on soil type, etc. there can be a lot of changes.

Why is this? 

This knowledge will help you answer any questions the seller may have

  $540,000...this price includes no commissions.

Quote from @Marc Shin: First, you should let us know what state/city you live in because the rules sometimes change, and we can't give you solid advice without knowing where this investment is.Generally, you can give them a 30-day notice.

I don't think we will ever have enough "doors" to replace an income in this time frame, but we would like to get to 5 doors in the next 5 years which we would sell in 10-15 years to help supplement our retirement income.  

If so, any law firm or agency you can recommend to help with this?

Here’s the idea behind "Tonka thinking" (I came up with this quote): just like you wouldn’t replace a tire until you’ve got every mile out of it, the same goes for parts of your property, like the roof.

(Ask this to confirm the answer to #3 above is correct.

*This post does not create a CPA-Client relationship.