where i am at, ... custom glass from a local(ish) glass manufacturer (not distributer, but the manufacturing plant)
10mm sheets, 4'x2'x18" (90 gallons) (shallow instead of the typical 90 gallon tank)
in canada we tend not to get upset about being ripped off (that's how i look at it, i don't like being ripped off like this though)
in the US the cost is about 1/2 that
a regular 90 gallon aquarium - $300 (canadian site)
from thefind.com (i think it's US only), prices seem to start at 250 and up
as far as price compare, custom order for glass is slightly more than a standard 90 gallon tank.
i have seen a US site (in california) i could get the glass for about 1/2 the cost, but shipping would move it to over $500, ... not so good.
but that's all glass,
it emphasizes the cost of glass
acrylic is one site (prices may be outdated as they're not a seller themselves) ... listed about $750-$1300 (i'm going to guess US prices and distributors)
so that's 3x to 5x the cost going by acrylic.
if you need acrylic, go for it.
if you're after the looks, ... your choice
if you are rich, by all means
just know what you're getting into
not saying go 90 gallons instead of the 40 gallon breeder you're after
it's the bit of research i did looking into prices myself ...
in the end, i'll summarize it this way
glass DIY vs. finished tank, ... (shipping aside) DIY is ... lets say about 1/2 the cost in the states, (and slightly more than a completed tank in canada)
glass finished vs acrylic finished ... acrylic is over 3x the cost.
just know what your budget is and decide if it's worth it ... some fish it's worth it as they are known for breaking glass tanks (same with some shrimp - mantis shrimp) but ... know what you're doing and why.