We are currently using MOXA 405A 5 port managed ethernet switches connected in a ring topology because we need redundancy / dual path between any two devices, we also need QOS. These switches are kind of expensive yet the manufacturer describes them as "entry level". What determines the price of an ethernet switch - is it the amount of memory or the amount of software features or the switching speed or what? Are there any cheaper managed ethernet switches that provide redundancy/ ring topology? They need to keep their configuration settings whilst powered down.