My understanding is that SP does not "offer" equal features, that, it seems, is a nonsense. What it does offer is a developer's dream, or nightmare, depending on your point of view. If developers have sufficient skills they can develop custom modules. I understand there are shells, basic plugins, that can be developed further, but my information is that the shells are not necessarily of the highest standards. Having said that, please understand I do not know of my own experience, but I am going on what others tell me - and they may not necessarily have it right.
The real advantage of Moodle is that the plugins are already at a usable level, that support is freely available, and unstintingly given. Given the nature of PHP, you can adapt existing plugins, or create new ones to suit yourself. For SP, my understanding is that basically, you have to start from scratch. This means not only are you required to build the plugins but you also need to debug them individually, and on top of that, debug them collectively. While Moodle is not perfect in this regard, you can be sure that if you have an issue you can at least get support for a fix. In SP, where is the support? My impression is that it is all self development stuff, so where are you going to get support for that?
In the end, it is entirely the decision of the people who are paying the bills, keeping the accounts and funding the organization's financial structure. I suggest costs will be lower with Moodle than with SP, a lot lower. The development cycle alone will be a lot shorter, keeping costs down further, and support costs can be amortized over a longer period. Moodle, for me, is a more cost effective outcome than SP, even if the idea of SP is a lot more sexy to a developer. Practicality must determine the outcome - and the largest part of that practicality has to be costs. That is something Moodle users do not really discuss, btw, but you could get that topic on the agenda, and I suggest it might be a far more successful argument than talking about the Open Source nature of Moodle.