i'll agree with all of the above, i haven't seen a kit retail online or otherwise for less than 200-250 dollars. for the really fine kits you're looking at double that and up.
some folks might opine, that it's better to start buying the parts and hand-fit them together. i myself built a semiauto years ago that way, buying one or two parts at a time and fitting them by hand. it took more than a year, but it was a wonderfully crafted piece of work.
doing things one part at a time will give you a deep understanding of how it all goes together and works together, and if you use jeweler's level tools and fine-tooth files only, your fitting will take a long time, but if you file, check, file, check, file, check, ad nauseum et infinitum, your fits will be in the ten-thousandths of inches, and the resultant gun will be a beautiful peice of work.
but you probably won't want to do that for your first kit. it's far more fun to be out there banging away, but do go slow, remember you'll get what you pay for, and shop around.
maybe some of the gun stores in your area might be able to help you as well, and perhaps the local gunsmiths. many of those guys will enjoy answering questions if you ask nice and listen well.