I'd say lights and co2 system is going to cost the most. The tank itself if also a pretty penny, if you want a nice one. Rimless tanks are gaining popularity, it doesn't have any of the plastics that standard glass tanks have. They cost a bit more, and harder to find, but places will ship.
Lights and air pumps are actually fairly cheap. You can get decent pumps for under $30 bucks same with the lighting if you go to home depot or some other hardware store for the bulbs. Most of the tanks you buy come with the light fixtures already. And yes rimless are gaining in popularity, but they are made from acrylic plexi not glass. Some are glass but without the rim they'd have to be small since glass doesn't have much flex before it's breaking point. Thats what the rims actually do is help keep the glass from bowing to it's breaking point. I took a 120 gal and made it rimless before I knew about tanks, But after the 3/4 full point the glass bowed out so much toward the top it busted like a balloon... Got a 120 downstairs now that I just put new seals in on,, Letting it set for a while before I run it. Got it free. Some one didn't take care of it and let the acidity of the water get to high ate out the silicon and made it leak. I cut it apart and rebuilt it. I did a quick hold test on it for 3 days and it held great. I've made some wicked tanks. I've mended 2 10 gals together by cutting the ends out made a 20 long.. I made this terrarium out of 2 10's Made our snake tank out of 2 10s as well . I've even gotten good at popping my own glass to make tanks. I love aquariums. Before we started to move we had 2 30 gals a 120, and 7 10s, we're down to 2 30's and 2 10's right now. the day we move everything will be in one 10 gal I chambered and built a battery powered filter and pump for the 18 hour drive. The fish should love that.. lol
All of the rimless glass I can order or see in the stores ARE glass. Acrylic or plexi do come in rimless, but they have pieces of plastic on top for bow or whatnot, not as clean looking. And most rimless tanks are of smaller size, bigger ones usually are short, so it doesn't bow as much. My next tank will be a rimless tank, for my reef Lights are not cheap if you want great lighting, any cheap lighting can be bought or made from home depot, but not as strong as metal halide or power compacts, which aren't the cheapest forms of light.
Wont argue that point at all. Very true. However getting into that kind of lighting, you have some serious plant life and expensive tropical fish with specific lighting needs. In which case you got money to blow to begin with. Even the little rimless tank you showed a picture of, if you look closely has corner snaps on it. But yes they sit lower to reduce the bow factor. I still prefer plexi, it is stronger than glass. And like I mentioned, it's easier to make your own custom tanks out of it than glass, as with glass you're limited to right angles unless you order pre curved glass which gets costly. But you make good points none the less so I have no argument to any of your comments. I just wish I had the money to run some set ups like the ones you originally posted..