I don't think anybody can be precise about the # of hrs required for currency amd I didn't intend it to sound that way.
One thing is what one is flying, how well equipped it is and how much of the stuff works. With most people having to make do with very old planes, it is always controversial to suggest that a decent plane makes it easier, but it does! But a decent IFR plane is likely to cost upwards of £100k, and that is a 10 year old specimen. A new one is say £250k. But on something like that you may need only half the currency. And I am not referring to flying the ILS with the autopilot (which does make it awfully easy).
It comes down to cockpit workload. In training this is high and intentionally so. In reality almost everybody who flies IFR for real has a nice big GPS with the route programmed into it. One would track VOR/DME/NDB, as available, concurrently, to eliminate most gross errors and to have less work if something packed up. This way your workload is far less than you've ever seen in training.
Holds are flown very rarely in reality, and when they are they don't need to be perfect because the protected area is big enough for a 747!
Another one is autopilot. Only a masochist likes flying in IMC for hours - all it achieves is that you arrives tired for the stuff which really needs your brain. If you have an AP, you use it. I fly manually the last 20-30 miles but occassionally I do an ILS with the autopilot too.
I am starting on my FAA PPL/IR now and allowing for the max credit from the IMC Rating training one might need another 20 hrs or so, at say £50/hr plus whatever the plane costs to hire. So that makes it say £3000. A standalone FAA PPL is going to cost some £1.5k.
Regarding IFR departures, it isn't necessarily the case that the ATC actually does anything else beyond a) reading you your IFR clearance and b) making a slightly greater effort than usual to ensure there isn't somebody in the way. Certainly I've had IFR departures with no onwards contact arranged. However if departing into real muck I've generally had the next contact sorted - but then if the weather is bad enough for genuine IFR the radio will be pretty quiet anyway, and one can get RIS from big airports...
Finally, one can't be above the MSA when taking off or landing
