The IMCR is technically easy - what makes it nontrivial is the fact that most people are going into it with zero instrument experience and are doing it in aircraft in which barely anything works.
You want to try teaching it then, 152 ADF approach can be interesting, with a good wind.
I would agree with Peter, some people find the rating quite tough, however Ive put them in fairly capable faster aircraft with HSI RMI GPS etc and then find it much easier, however most cannot afford such training, unfortunately.
I was clearing out some old files yesterday, and my old school in 2003 was doing IMCs for £1500.00. Now nearer 4.5K I would think.