Zooplas online estimation is interesting - but actually in some cases in hertford it's horiffically wrong. Mandeville road is an area where it has no clue - primarily as you say because there are no sales.
Thanks all. Chose one of the "old lot" and one of the "new lot", so far have seen one of the older established agencies and very impressed. Seeing one of the very new lot later today. I expect to be impressed by them too as an initial valuation is pretty much a sales job anyway,