I used to work in the industry - just thought I'd give you a couple of pointers:
- RSA are known to be expensive and market themsleves as a broker focused insurer - i.e.they only want business from brokers - this can can mean that they are not necessarily as competitve as direct insurers becaus ethey don't have to . Although sometimes bigger brokers can negotiate great deals - depends how much business you have with them.
- There are a lot of Agents such as AA, 123.ie etc. that have huge contracts with different insurers that results in massive savings for the agents which they then pass on to their clients. It wouldn't be unusal for a policy through an agent (not a broker) to be substantailly cheaper than a similar policy from the same insurer direct.
- Check carefully what both policies cover - sums insured, excess, accidental damage covers, all risks cover etc.You may find on the cheaper policy that there are a lot of add ons involved (to match your current cover) that will end up costing you.
Generally it can really pay to shop around in this area of the market.