As I understand it, your goal is to reduce your expenses. That immediately means don't replace anything you now have, unless you can sell what you have for more than you will pay for what you would replace it with.
Your monthly plant related expenses include electricity, CO2, fertilizers. Your light is way too much for a low light tank. If you can sell it for a good price you could save a little there. Or just run two widely spaced bulbs, put a layer of fiberglass window screen over the light (cuts the PAR by 40%) and have it at about 24 inches from the substrate.
Since you already have the CO2 system I would keep it, and reduce the bubble rate so you have around 20-30 ppm of CO2 in the water. That should cut down on your CO2 refill costs. You can then reduce your fertilizing to about half or less of the EI dosages, slightly reducing that cost.
None of those cost reductions will amount to much, but you should then have to do far less tank maintenance, spend a lot less fighting algae, and save a little more that way. I think I would just sell this change on the reduced work involved, the more relaxed approach to tank maintenance, and therefore more time to wine and dine your wife (killing all of the cost savings, but greatly reducing the wrath.)
Thanks for the input, I think it more than reduce expenses, but also reduce the time working on the tank each week. Not much time as it is now, and that only to be less soon. What are your thoughts on substrate with info I posted above? So with the light I would just wrap the screen around it? checking now with the light I am at 23 1/2 from the substrate, no room to go any higher. In regards to the ferts I would be fine not having to do anymore of that. Is that any option, but assume I would need to do away with CO2? My CO2 now, I don't even know how many bubbles I have, cannot count, but does change my drop checkers to light green. Sorry for all the questions, just trying to get this right this time.