Hi Erin,I hate to give the generic answer, but it will depend on the specific situation.

So it really depends where you are.Have you tried CL?

As @Pete Schmidt said, it'll depend mostly on the buyer and seller, what they need to make the numbers work, etc.

Talk to a lender, you may even be able to get yourself into a duplex or some other multifamily depending on your area.

Michael,Market's definition is dependent upon the population size in general, but you should also look at the supporting factors such as the infrastructure, job market, etc... 

Whether it is a positive or negative one will depend on you, but it will be an impression nevertheless.Best of luck and keep us posted!

Like I mentioned in the post, there is a door between them so it can really practically operate as either a duplex or a single family depending on the group and their preferences. 

If I move it, can I refi it later after the typical 6-12 months (depending on the lender) or will it be treated like new construction, which I believe would need to sit a lot longer before a refi?

depends on the state. 

Grant street group and ********** are two sites that run tax sales for many counties around the country.How much to start with depends on your financial position.