The X1 is very popular. Since there are so many of these things out there, the potential of getting bargain priced parts, namely bulbs, is better than with less popular projectors. All things being equal, it is usually better to choose the more popular model of anything, cars included. This means getting replacement parts and service should be easier. This is an intagible you should consider when choosing projectors.
Also closely look at warranty and bulb life. The X1 is serviced by Infocus who are excellent with warranty work. A Dell projector will usually have a shorter warranty and much more iffy service.
I love my X1, which I've had for a year. I still have less than 1000 hours on the bulb, so the bulb should be good for 4 years.
In the past, BH Video had pretty good prices on screens. I got a Da-Lite 70" wide screen that hangs from my ceiling for under $100 shipped. This 70" yields an 87" diag 4:3, and an 81" diag 16:9.
<a target=_blank class=ftalternatingbarlinklarge href="http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=15137&is=REG">
http://www.bhphotovideo.com/bnh/controller/home?
O=productlist&A=details&Q=&sku=15137&is=REG</a>
Go to BH Video and put Da-lite matte in the search box. Sort low price first. Many of the low cost are just screens, which you could tack to a wall. The ones that pull down or have a stand cost more.