text: can i get an on-line home appraisal?   yes, but they're usually only as accurate as they have tax assessment data or other not so accurate data. the fact is that even when you bring in a professional agent, they do what they call a comp, looking for comparable houses in your area, they're still not always accurate. unlike cars with an msrp, houses have no absolute value at any given time. the value is what you get offered, but you have no offers yet. if you have time, start 20% or some other number, higher than the comps the agents pull up. get an agent to pull some comps. try to work an agreement with an agent that can be shelved for some period of time to reassess the listing price.