I would have thought that the cost of a renewal is relative to your own ability and amount of IFR flying post qualification to a large extent? When I was doing my initial IR I saw quite a few guys coming back to renew their IR's. The majority hadn't flown since getting the IR or had been VFR burning holes in the sky if they were in the fortunate position of having any spare cash left over to be able to keep current. It cost them a lot as the school was expecting them to be on top of SOP's etc. It certainly wasn't a tick in the box. Wouldn't have thought much change from £1k.