a lot of people are upgrading their backs to get an IQ... so there's some refurb back available... (i still can't understand how all this photographers can afford to get an IQ180... in my area, it's just impossible for most of us..., but that's an other topic... ).
So, if you were shooting architecture on a RM3D, ( and money is a concern )... and your shooting style requires around 30s exposure...
will you go for
i prefer leaf colors, but i don't have a lot of choice...
DM33 (i don't like the ratio of the aptus II 10, and can't afford the 12)
P45+ (long exposure for shure)
P65+ (more recent, and bigger... for more money, i can't afford something more expensive than it ! )