I've been sitting in the middle of this process for 3 years now including getting very close for PfS and their ICT team.
1. The default position for Academies being built and funder under the BSF programme is that their ICT will be provided by whoever the Authority appoints. However, they will have the right to ensure their specific interests, values, specialisms etc. are fully reflected in what the ICT provider is offering. That's why there is specific funding to get in professional consultants to help through this process --- this from the Becta framework.
2. Academies can opt out of the Authority provision (and some of the consortia Academy sponsors: Ark, Oasis, ULT have the capacity and purchasing clout to do so), and there is a formal process for so doing. But it ain't easy. That's why it's vital academies keep on top of the BSF process in their authority and keep banging their own drum.
3. Good ICT technicians and managers will never lack for secure and profitable employment. Most are underpaid and undervalued in comparison with what they could earn outside in industry. The service level agreements demanded of the ICT providers under BSF will be so stringent that they will need to engage positively with existing ICT staff, and my observations of these providers recently (can't say where) is that the good ICT technicians and managers should look forward to a rosy future --- with a helluva lot more training, career development and benefits.
4. And if you don't like RM's price list, tell them exactly what you want, how much you can get it for from your own supplier and demand they deliver. RM are very touchy and vulnerable these days and are 'bending over' to break with past perceived restrictive practices. Good luck!