Thing is, I have limited funds to buy this stuff lol.
Most of us have the same problem...
I'd put what you have together, make sure it works. It's not as easy as you might think.
Then I'd add more solar panels and batteries as the money becomes available. You need at least one more battery and two more panels before you need to expand the other parts of your system, so right now at least part of the initial cost is covered.