owner finance question

[TJ Addison]

If you were to purchase a property from someone who wanted to do owner financing it is safe to say that they would like to be the bank on the transaction and bring in a monthly income with a nice yield. 

If you are on the other end of an owner finance deal, is it unethical or looked down on to refinance out of that after say a couple of years?  I guess my assumption is the person providing the owner financing is most likely looking for monthly income for a long period of time so that they can collect all of that interest.  They don't probably need the lump sum amount either.

Is this situation usually written into an owner finance contract i.e. you can't pay off the loan for "x" number of years?

I'm curious to here the response on this because I am looking to try and find a property that I might be able to owner finance but I'm not sure if I want to pay a higher rate to that person long term if I can get something lower at a bank.

Thanks

TJ