Hi Benjamin-
Read Dick's response (above). He speaks the truth.
About 30 years ago I was doing what you are. Skipping the details, it took me about 6 years to determine that I had set myself up in a dead-end business. No money for expansion, no money for all but critical maintenance, no money for a life beyond gas money, groceries and utilities.
Eventually I sold off or gave away most of my personal gear and went to work for others, managing and operating. I used the 'education' I'd received from the University of Experience (and some of the formal kind, too) to help them avoid, on a larger scale, the dead end situations I'd put myself into.
Thirty years later, I can tell you the income potential has not changed. In all but the more lucrative areas, you will not make a living providing sound for bands who play bars. Slightly up the food chain are bands that play society weddings, small corporate events (such as may still be around), etc.
The issue with serving bands is that they are spending their own money. There is tremendous pressure to keep contracted services as inexpensive as possible. The best profits exist in serving markets where your fee is paid with "someone else's money."
Make your purchasing decisions with a forward-looking eye. Size, weight and the ability to put in and take out by yourself, relative ugliness of gear in public view are all factors. While we can and do discuss/argue over the sonic merits of a mixer or speaker, realize that most of the people paying your fee can't tell the difference. They only know if you were easy to work with, if there was feedback, that you gear looked well maintained, etc. Keep those kinds of things in mind.
And cables? At your point either go with Mark & Liz at Audiopile.net or learn to make your own. Great folks selling honestly described and fairly priced products; you'll like buying from them. I purchase all my 'kibbles and bits' adapters, short XLR cables and lots of misc. from them.
Have fun, good luck.
Tim Mc