Undisputed, I think if you make it to about $1,500 you can do it. And that is at the high end of your time estimates at 60 days...it gives you a luxurious $25 a day. Riding East to West, make sure you capitalize on the free lodging opportunities. As I mentioned in one of my replies here, I have planned 48 overnight stays that are virtually free. Bear in mind that it is good manners to leave a small donation at churches, and maybe bring something to the dinner table of Warmshowers hosts. Of those 48 overnight stops, most of them are on the first half of the E-W route. After that overnight costs go up because of a lack of free overnight opportunities, of course stealth camping is the exception.

I think you can do it...if; you include cooking a majority of your meals, capitalize on free overnight opportunities, make motel stays an absolute rare occurrence, and shorten most of your days by at least 20 miles.

As some have mentioned, your mileage is way optimistic. When you get into the Appalachian Mountains, those miles are going to be somewhat painful. Some of the distances required are long and necessary due to a lack of overnight opportunities. Many riders have classified a couple of those days as some of the most challenging of the whole trip. I know from experience that they are tough as chewing on shoe leather. There is some pain associated with climbing all day long. What goes with that is a critical mindset...many riders have given up their dream trip when they got into those mountains. If you're considering hundred mile days while crossing them, you may be setting yourself up for failure. Maybe not, but you will be worn out by the end of each day; the attraction of a motel stay might be hard to pass up, resulting in motel stays that might throw you off your budget.