When I do an estimate on a trashout and I see we'll need a dumpster, I include that cost in my overall bid. I do NOT, however, break the bid down so the client sees each individual portion. I only do that after we land the job -- "if" they request it for in-house accounting purposes. Reason? I don't want them using my bid to "shop" various portions of the job. Include all your costs when you give a bid. A dumpster, if you will need one, is a real factor and can be a big chunk of your costs and will dig right into your profits.
Good luck. (See tons of info at the link below on starting, running and profiting in the foreclosure cleanup industry.)
Cassandra Black, CEO, Foreclosure Cleanup, LLC