There are discussions about this on the board, but a quick recap, as I have considered the same thing myself. Dozers are expensive to fix and break down somewhat frequently. I've never leased a large piece of equipment, but some leases, I've heard, either share the cost of repair or put it all on you.
Also, large area work often requires two pieces, the dozer and an excavator. What are you planning to do? Working on virgin ground is one thing, but working on an existing pond is a different critter all together.
I know of farmers around here (who are used to working with big equipment but not necessarily dozers) who have done this, so its not impossible. Hopefully some of the experts will chime in.
For me, it has been said that I have more money than sense (not a hard feat) and I will probably try this myself at one point or another.
