I agree with lou.. Every thing he said... and..

Your best bet is to have a few kits under your belt before you start a 'scratch built' plane, especially for your first. Also, with a kit, you'll see how some parts are put together, and why (somethings aren't obvious untill it's too late!)

Also, all teh parts are there for you, and pre-cut. There are methods to cut 20 or so ribs to be identical, but the set-up can be a daunting task. Again, with the modern 'laser cutting' of most kits, the parts accuracy is excellent.

While you buy the kit, you can save up for teh other parts. A kit is generally never a 'complete kit', and will require a few other parts, such as wheels, spinner, fuel tank, some hardware, covering, etc.. You can start with just the kit, and as you build, you can buy the additional parts as you need to. Assuming, of course, that you have a near by hobby shop.

And, from experince, the local hobby shop will never have all teh wood you require to build a complete plane, unless you visit them about 5 or 6 times over a few months! Murphy's law! (He'll have 5 of teh 7 balsa sticks you need for teh wing, and no 1/8 x 4" sheeting, just 3" which means butt glueing them together....) Sometimes it'll be more hassle than it's worth...

If you want cheap, and a bit of a 'scrathc built', visit www.spadtothebone.com, and see what they offer. These are planes made of coroplast, and are dirt cheap to build! In fact, you can probably get eh stuff for free, assumign tehtre's an election comming up in your area. It's the stuff they usually make signs out of!!