I agree that in theory paid parking within a complex is a good idea, the problem comes in collecting the money that people agreed to pay to be allowed to park their.
Would the fees be considered as part of the levy and so collectable under the rules governing levy payments (virtually impossible to avoid).
OR as a general payment with very poor chances of forcing a reluctant resident to pay.
Also who is going to administer it because allowing non payers to park their will antagonize those who do the right thing and pay.