Gotta respond in kind to anyone who does anything "respectfully" on the Internet.
Es[ecially a new member whose post seems to have been ignored. So let me welcome you aboard the DIY Screen Forum
Have you read any of the various Threads where people have completed projects and reviewed their results?
Most budding DIY'ers come aboard thinking thoughts such as you prescribe.
If you have never seen a large image projected onto a matte white surface by a high resolution PJ, in a environment that does not work to detract from image quality (IQ), your bound to be impressed.
But no "real budget MFG screen" will come with the ability to improve IQ. In fact. some do actually reduce IQ.
Brook no mistake, getting something that performs exceptionally well for a very low cost in time in effort is the goal of most DIY'ers. Yes, we get a large share of those who see an image on a bed Sheet or beige Wall and are so impressed they say, "Why bother". But that only shows the validity of my first statement. When such folks come around, we use a combination of input provided by them...sometimes with a bit of goading necessary.
Room Dimensions & Colors
Knowing the "actual" PJ being considered / chosen...not just an ambiguous reference.
Projector placement options
Seating arrangements / location.
Budget notwithstanding, most every DIY'er that leaves here does so with more value and performance than they ever thought possible. What is the real determining factor? It's "How much effort does the DIY'er want to provide to accomplish making a Screen that performs like a multi-thousand dollar Mfg Screen." (...or in the least, one costing many hundreds $s )
If you opt for a "Fixed Mfg.Screen", you actually pay more than for a retractable, because it is acknowledged that a perfectly flat surface is best. Those needing "retract-ability" and who also want "Flat" usually up the ante and get "Tab Tensioned Screens"...which cost much more than their non-tensioned counterparts. Also, opting for any material / color that is not a basic Matte White" usually increases the cost of a Mfg Screen (...if indeed that is even an option to do so...)
A DIY Screen can be almost anything desired / needed, and often exceed anything available in a Mfg Screen as far as size, format, and affordability. Some DOY options involving painting on a surface onto a solid surface are virtually infinitely adjustable to meet the specific needs and criteria of the individual and his circumstances. Almost no Mfg Screen line can even come close to that flexibility.
Sp...DIY Screen making is all about value AND
performance, and a important additional factor. Pride in one's accomplishment. And the latter often becomes the most noted item because the DIY'er is astounded by what he has wrought.
There has always been, and always will be those who will settle for less and pay more for the convenience of doing so. Ditto for those who must have the best and who will pay insane amounts to supposedly get such. DOY Screen making is almost always a case where the DOY'er wants the "best for Less" and all of us on this Forum are dedicated to seeing them "Get'ter Dun!"