If you think you have a strong arguement for a discounted membership, then take that arguement straight to the providers of PF & RP Data and ask for a discount? Maybe they already have a program to support small businesses?
Out of curiousity, if I was a boutique landlord with only a small number of properties & had only just started out my investment journey -would you offer me a discount on my property management fees? Obviously as a new investor I have a lot of start up fees, like insurance, stamp duty, LMI, initial repairs on the property, ect.