I got tired of climbing everything about 6 years ago and bought a bucket. Best decision I ever made. It more than pays for itself. I use it on 99% of my jobs, even in the winter. Get a few payments ahead and stay that way. Keep a little money put back for tires, batteries, brakes, fuel, oil changes, and an occasional D.O.T. harrassment.
Don't underbid your jobs just to get them. Sometimes it's cheaper to not work than to pay for the luxury of working. You will get underbid from time to time. Don't worry, these guys won't be around very long. Take care of your truck. Go easy on it and keep up with maintenance, wash it regularly and keep the saw dust blown out of the bed. That keeps the metal from staying damp and rusting.
If you start making decent money, don't blow it. Hang on to it because winter is coming. You'll need it then. Be smart about your advertising. I have my name and phone number on both sides of my boom in big letters. When you are working, it can be seen far away. You have to be as tough financially as you are physically to make it in tree work.
Stock up on a few supplies like ropes, saw chains, saws if you can, chain oil, files, and saw parts. Most of the tree guys around here use clevises or natural crotches for rigging. When I bought my truck, I bought slings and several different size rigging blocks, GRCS, Port a Wraps and anything I could to make my ropes last longer. They have paid for themselves and are making me money every day by not buying prematurely worn out ropes. I charpen chains down to nothing, tighten bar rails and level them.
Also with the bucket, if you get to be friends with other bucket owners especially Entergy, you can get some hand-me-downs like used outrigger pads and bucket covers.