Michael,
While helpful, all of the items on your list can be done without. But don't worry, they aren't all that expensive. Here's what you need for what you asked about.

1. Field Charger. You can get by without this one, but it is a flying session saver. It will let you recharge your plane and transmitter quickly at the field. So instead of getting 2-3 flights a day, you can recharge and keep flying. Hobbico makes a great one that will recharge just about any battery you have at the field, and it cost $44.99. You can find it at Tower Hobbies here: [link]http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXCTZ5&P=ML[/link]

2. Buddy box. You can buy this at Tower Hobbies, but I wouldn't waste money on it. Most LHS will rent you a buddy box for the time you are training. Or check with other people at the field and see if any of them will "loan" one to you. A buddy box can be any "plain jane" sky sport 4 channel Futaba radio. The funny thing is that most instructors I know all have the buddy boxes that they use with their students. I have on for every brand of radio out there.

3. Contraption to hold the plane. Tent stake and a piece of rope. $2-$3 at Wal-mart. Simple, cheap, and gets the job done.

4. Timer. Less than $10 at Wal-mart. Look in the cooking section for a digital cooking timer. Cheap and easy to use. Take your plane, stake it down, fill the tank, and run it full throttle on the ground. Time how long it takes you to burn the tank of fuel. Then set the timer for 30 seconds to a minute less when you are flying. This will give you some leeway to get on the ground when the timer goes off.

The field charger is going to be the most expensive on the list, but the rest are pretty cheap.

Hope this helps

Ken