I too, know about living on a tight budget. For 20 years I lived without any electricity at all.
Just when I thought all of my "tuffing it out" was over, the economy changed. The price of everything started going up and up. But living within my means has payed off in other ways. More and more I have been seeing lots of people having to get rid of a lot of there "big boy" toys. What was once under their shelters is now in the front yard with a for sale sign on it. At least I am not having to give up anything.
About "tuffing it out." If you do not have a battery monitor, such as the Bogart 2020, get one. Knowing exactly what is going on with your system is very critical to operating and maintaining it. As well, how to spend those precious few dollars on improving on the system to fit your needs.
Being able to, see, the amphours in and out. Knowing how the voltage fluctuates; hour to hour, day to day, month to month, and season to season can educate you about your system in ways that no thing or nobody ever could.
A battery bank can be a major investment. Sizing it to last for many, many years is imperative to say the least and you want be happy about the investment. That you made a good investment. The last thing I want to be sore about, year after year, is that I made a bad investment in a battery bank and judging by your posts, you feel the same way.
With a battery monitor, you can know exactly what your amphour needs are as compared to the amphours produced.
http://www.bogartengineering.com/trimetric.htmhttp://www.advancepower.net/metersys.htmhttp://store.solar-electric.com/tm2020.html And don't forget our host Alt E Store.