This product is very reasonably priced. There is only one version for this software, and it is currently $150 USD. Included in this price is the ability to setup as many guests as you need, as well as providing 50GB of storage for these guests. The subscription costs for this product are annual.
I am not the software author, and you will purchase software directly from the supplier.
I am happy to assist with installation, training, and setup support as required. The portal concept is easy to grasp, and requires little design. I suggest perhaps one to two hours of training and installation time is required to use this product properly. (i.e. $75 to $150 AUD)
The software is intuitive, and will be picked up quickly.
Great service for your clients!