It's the signature of the Registered Valuer which is essential for the report. U can give valuation yourself if your name is on the Board of the Valuers!
Afaik the more expensive your property is, the higher it cost for your valuation report. There is a guideline for the valuers to follow on the cost of the report...

Though you can try to negotiate with the valuers on the property value (try to hike it a bit by mentioning special features of your property, such as renovations done etc)
Well this is the case of you wanting to get for more loan...

PS: newbie here, any mistakes on the comment given pls guide me.. (with soft tone lol, still in learning progress here.. @.@)