I want that too! The 180 I have now with stand, canopy and tank new would be over $3000. Tank alone $1100. The pentairaes are nice. I was looking at the 96×36 somehing or other I think it was 700g $2000 that would be a great way to go. Not sure if going plywood would be any cheeper in that size. Glass for the viewing panel seems to be alot of the cost on those builds. Was researching building my own wood was around 300 then epoxy was another 300 -400 a piece of glass for a 30" depth 3/4" was 1200! 24" 1/2" was 900 @7' long. Then all that work....... those prices didn't include a stand or canopy or 100ish for screws. + whatever else would be needed.
I think 1500 is asking alot. You are going to need to pad the budget a bit. ×2 at least. Or get lucky with used.