All these feelings from one lmgtfy link.
I could retort at all the crap you just spewed, but I ain't got time for that. I will say I've never (nor will ever) charged anyone even close to $1000 for artwork. Heck, even $600 is on the high-side for what I charge and that would have to be a heavy bit of work -- meaning a full art-set of 40+ characters re-imagined in a completely different yet cohesive style.
Listen, just start by googling some online tutorials, getting used to Photoshop's interface and tools. You'll notice there is a Shape tool --> this is the tool for making squares. There are plenty of tutorials for the basics on youtube that you can easily learn from. Aside from that, photoshop's help files are great for learning about each individual tool by themselves.
As for knowing how to make appealing artwork, well that's something you can't learn overnight from tutorials. I would suggest studying good-looking existing arcade cabinets to take queues from. Look how they use the space to their advantage. How the colour choices work together (I'm not going to explain colour theory here), how the objects are composed, and how clear and concise the artwork is to conveying the theme and style...etc...
As for the little tricks within photoshop, again there are plenty of tips and tricks floating around out there, but most of the techniques you'll learn in PS will be from working on the art as you go on.