New to AV. Lot of projectors getting high reviews on this site for $2500. Is there that much of a difference between a epson 8500 and something like the SIM2 D60 for $5k???
SIM2 is going to be a bit nicer build overall, and is a very solid brand.
But, if you are asking if there is going to be a huge difference, than I don't think so. Sim2 has limisted distribution and protects their brand name through this, but that doesn't actually mean that they are truly delivering a product which is significantly better than what you can get for a fair bit less.
This is also true of Digital Projection, Projection Design, and (blech) Runco.
If someone is doing a really nice home theater, with sound paneling, and fully installed by a custom installer, than going with a more boutique brand which offers a slight jump in quality may just be part of that expense - which could easily top $100,000. But, for the do-it-yourself folks, or those on a $10,000 or so total budget, than the Epson/JVC/Panasonic/BenQ options out there for $3,000 or less are phenomenal choices and deliver upwards of 90% of the quality pretty easily.
Keep in mind, the rock bottom online pricing you get is not going to be matched if you are NOT installing it yourself and you should expect to pay a 10 to 20 percent premium to any custom installer who has to receive the package, order it, and typically service and warranty it for you for a year after installation... oh, and they actually have overhead expenses and need to make a profit which 10% (or less) markup simply doesn't provide.