I'm thinking to get RPData Professional subscription for $79 - 3 months access:
http://www.myrp.com.au/n/Investor-Insight-Tool-Subscription/myrp-1177
is it better than PriceFinder, APM or PropertyInvestar ?
and last question, is it tax deductible as well ?
I prefer pricefinder.
It's tax deductible depending upon how you're structured and level of property involvement. For a IP newbie purchasing in own name I'd say not. If you're primarily a professional investor, Id say yes.
Obviously seek professional advice though.