Shamow, first off, personally I wouldn't let "learn to walk before you can run" put you off. Nothing wrong with aspiring to something.
Running an IMC capable plane is not by definition significantly more expensive in the short/medium term if the avionics that are already in it are new or at least in good condition. But when something goes wrong it can be costly to put right and fitting fresh FM immune avionics is expensive. The point that was made by ChilliMonster is very valid, so don't ignore it just because it was made somewhat condescendingly: if other group owners of the plane have no need for such equipment they may well be reluctant to spend the money required. Even VFR pilots might like a working transponder and a VOR, but they probably don't care about a second VOR, a second comm radio, an ADF, glidescope, second altimeter (for airways use), etc.
The best way of staying current is to fly in a group of IMC holders who want an IMC capable plane, but with at least one other IMC/IR holders who actually uses it regularly. Then you can (a) learn from them and (b) help one another stay current.
The prices quoted previously seem reasonable and meet with my own experience. Planes for sale at around 30-35K may have all the equipment but it will likely be old and may require attention - new kit can cost several thousand pounds to supply and install. In a 50k-100k plane you might expect more and newer avionics. Monthly fees 50-100, hourly 50-100.