I've had that done on properties where there are truly no comps I can use and defend. It has always worked well for me in terms of getting my listings sold at the "right" price and getting appraised by buyer's lender.

my wife sometimes recommends it if the sellers think she's lost her mind.

I find it ridiculous both before and after the sale.  We rarely have properties appraised and do not give the Appraisers the same power that you do in the US.   We don't rely on their opinions up here. 

I don't see a need to hire an appraiser to estimate the value of a property prior to sale, unless it is a very unique property where the sales comp approach we all use will not apply.

On occasion over many years sellers want an appraisal (for whatever reason). Also divorce attorney will want one as well.  The other reason I can think of is if the property is so unique and there are simply no comparables close by and or closed in a long period of time.

Like prior home inspections, they do seem to head off future problems for some.

I have had to do that for divorce sales and unique properties. 

I agree with doing it under those circumstances as it's necessary and often required.

What Nina Hollander said.  I listed an older farmhouse on small acreage, 20 miles west of town.  There was no way to comp that house.  So, we brought in an appraiser to set the asking price.

They can help set value whether for sale or for lending purposes. There are some people and properties that lean on them to get started

"..services of a property appraiser....:

??? Hmm, they could throw in a car with with every appraisal. That is a service I could celebrate.

But in this real world the only difference between A and B is the quality of the report (not the data)  and whether the 'goal' (not value) was achieved.

The report is a heads up to the seller and agent regarding how the property should be positioned in the marketing plan. The appraiser does not help much with that.

There are times we have no comps, or the homeowner has added square feet.    Have had this done a few times.

This is helpful - especially when you have a seller who wants more than the  market dictates and it may bring him/her down to reality.

what are you?

I've enough coffee and I just cannot dig deep enough on this to get to what you are asking here.  

Isn't an appraisal an opinion of value?  

What services prior to valuing a property?

Not following your question ?

Opinion is neutral - the appraiser has a task to do. There are several reasons that one may need an appraisal for - it's not just for determining the ”value” for a mortgage loan.

I have appraised a lot of properties but am uncertain of what you are asking.

I don't think it's necessary unless the homeowners' idea of the worth of their home is out of line, but those homeowners would not be likely to get the appraisal anyway.

If they know the area and is tough to find comparable properties, a Trust sale or an ensuing divorce, then yes.

Otherwise, I believe a good agent can value property - I mean, we share the same comps and chances are, we've actually been IN the properties and know them and the location even better than the appraisers!

I usually recommend an appraisal for very unique properties. Estate  and divorce situations usually have had one done or are in process bt the time I get involved.