Its definatly one of the most costly areas of photography to get into - the long lenses are not cheap and the rest of the kit you need (hides, walking boots covers) can also add up to a hefty sum as well.
But don't look to the body first - look to the lenses. A top range lens on a beginner level body will perform surprisingly well and its far better to invest in lenses (which tend to not only keep their value, but are also not upgraded at annual rates!) so a 300mm f2.8 will keep its value and its quality for far longer than a 1D body.
MY advice for starting out since you like landscapes and macro is to follow those two first - since the lenses needed are cheaper (heck for the same price as a single long telephoto lens you can get yourself a camera body, macro lens, teleconverters, tripod, flash and some more!) Macro is very addictive and hard to tire of easily (least that is my finding).