Rockin' regards, Marco
It's easier to forecast expenses -- you know how many engineers you want, and can guess at legal, rent, etc.
But it's also good, if you can't have a market ready piece of hardware within two years, to have an alternate source of revenue in the beginning. For example, you could sell a suped-up (expensive) early-adopter version for a year which will serve as a prototype for the real (cheaper) consumer version.
Plan to sell very little in the beginning, as that's what always happens in hardware. And consider planning to sell through someone else. For example, if your device has to do with telephony, assume you will sell through one of the major telephone networks in your area. Then guess at what percent of their users in your target market area you can convert in the first year and calculate your cut of the sale. It's easier to estimate sales if you're thinking about taking a bigger and bigger slice out of a large, defined pie (rather than growing from nothing).
I just added this for you. It should do the trick. Just use the tab labeled "income statement_b" at the bottom and ignore the stuff in the other tabs. Then you can just swap in your own numbers.
In terms of figuring out sales, just figure out how many units you can sell per day. If you are in an incubator then you're probably going to be the only sales guy, at least until you hire another. Here is what Guy Kawasaki has to say on the topic:
Have you benchmarked sales figures for similar products as a possible baseline?