For the glass alone for the 57G rimless its going to run you around 150-225$ depending where you go. Your going to spend about 3-5 hours building it if you've done it before and spend extra for the overflow glass parts, silicone, masking tape, bulkheads, ect. Thats another 100+$ in your time (time that you can spend making more money or doing other productive things) and another 20-40$ in extra parts. Im not counting the time its going to take you driving around and getting all the parts. Just going to order the glass then going back to pick it up is going to take you about 2 hours of your time.
In the end it really comes down to the same price if you count your time put into the project with building the tank yourself. You also have 0 warranty on the tank, and if your not experienced in building one, one mistake can cost you thousands.
Go buy the 300$ rimless oceanic or if you want to save yourself $$ buy a AGA tank and pay the 1$ per gallon. I built all my tanks and said I never would again after my last one. Its really not worth it.