We are made of molecules (mostly water and carbohydrates)
These molecules are made of atoms, which are sometimes referred as elements, as in elements of the Mendeleiev Periodic table. These are NOT the 4 (5?) classical alchemical elements of earth, air, fire, and water (with sometimes metal or wood making an appearance in the list).
Water, for example, is made of two atoms of the element Hydrogen, and one atom of the element Oxygen. Carbohydrates are complex arrangements of Hydrogen, Oxygen, Carbon, and traces of other elements (traces that are still a round number of atoms. Most carbohydrates are much more complex than the water molecule and are made of more atoms)
These atoms are themselves made of particles called protons (charged positively), electrons (charged negatively) and neutrons (which are electrically neutral and serve as "glue" to keep oppositely-charged particles from repelling each other. The difference between the different kinds of atoms is the number of protons and neutrons in their nucleii (but the proportion of neutrons to protons is fairly constant). The number of electrons orbiting every atom can vary, giving the total an electric charge. We call electrically charged atoms "ions".
Now for the origins.
The molecules are formed from atoms or other molecules via different and complex (for complex molecules, like DNA and other carbohydrates) or simple (for simple molecules, like water) chemical reactions, IE reactions involving only the electrons, that have a tendency to "glue" atoms together in the right conditions (if you want to know more, you will enter the chemistry textbook area)
The atoms, other than hydrogen, are created via nuclear fusion. Nuclear fusion occurs naturally in stars (due to the intense pressure brought on by the star's own weight, pressure that translates into heat, and the heat does funky things to the hydrogen atoms). Our star is hot/big enough to produce atoms up to Iron (that is, atoms of the same atomic wight as Iron or lighter). The heavier atoms (plutonium comes to mind) come from older, heavier stars. Since they are not "produced locally", they are scarcer in our neighbourhood. They were trapped inside the earth when it formed.
Hydrgen atoms form spontaneously when an electron and a proton meet (and the temperature is low enough, but I believe the plasma point (where hydrogen breaks down) is several thousand degrees celsius.
Electrons, protons and neutrons are made from subatomic particules that we are still trying to understand (hence the much-decried LHC). They were made during the big-bang. All of them. What happened before the big bang we do not know (as in KNOW, not "believe") and probably never will know for sure.
Now, it is true that with 10$ (or more in order to account for inflation) you could buy enough water, carbon (in the form of coal or graphite), and the other trace elements present in our bodies to "build" a human body.
However, the building itself would be very complex. That is like saying that the Mona Lisa is worth the costs for a gallon of paint, one square meter of canvas, 5 meters of two-by-four (for the frame and the brushes' handles) and the hair from two squared centimeters of a pig's body (for the brushes). I can give you these things, but I doubt you'd be able to make the mona lisa out of it.
I hope I have been clear, and that I won't be TL;DRed.
edited for spelling, but I probably missed some...