Re: The cost of chemichals

The short answer is "yes."  There are a number of factors that influence 
the cost of a reagent.

COST OF SYNTHESIS:  Especially for natural products, the synthetic 
procedure can be multi-step and require dozens of hours on the part of a 
highly-talented (although never highly paid) laboratory technician.  There 
might be scores of different reagents used.

COST OF PURIFICATION:  Making it might be simple, but getting it pure is 
often the greatest challenge. It might require tedious distillation or huge 
quantities of expensive silica gel for chromatography, plus the cost of 
solvents and the cleaning of glassware when done.

COST OF ANALYSIS:  We must make sure we have the right material before we 
send it out.  That might require nuclear magnetic resonance or infrared 
spectroscopy, and possibly mass spectral analysis.  Both the identity and 
the purity must be certified.  All of these things cost in both time and 
money.

COST OF SHIPMENT:  Sometimes to make the stuff here is so expensive that 
companies will look for it abroad.  They might be able to import it from 
another country, but that requires import duties.  They also must be 
licensed to transport hazardous materials, and very likely must employ one 
or more people simply to handle placarding and permitting and other 
shipping issues.

COST OF WASTE DISPOSAL:  Now that the material is made and purified, we 
have to get rid of the waste that was generated.  That might include 
flammable solvents, heavy metal reagents (like osmium tetroxide or 
amalgams), highly toxic materials, etc.  These can be incredibly expensive 
to haul away.

MARKET:  Remember, chemicals are sold on an open market, which means there 
is competition, and for some chemicals, a lot of competition.  A company 
cannot afford to inflate the price of an individual reagent beyond a 
reasonable profit margin, because it will not take long for its competitors 
to start undercutting it on the cost.

As for leptin itself, I cannot answer with any authority, because I do not 
know the actual manufacturing costs.  But considering the structure of 
leptin, I would say that $45 for half a milligram is actually very cheap.  
Leptin is a rather lengthy protein:

MHWGTLCGFLWLWPYLFYVQAVPIQKVQDDTKTLIKTIVTRINDISHTQSVSSKQKVTGLDFIPGLHPIL

TLSKMDQTLAVYQQILTSMPSRNVIQISNDLENLRDLLHVLAFSKSCHLPWASGLETLDSLGGVLEASGY

STEVVALSRLQGSLQDMLWQLDLSPGC

Each of those letters represents an amino acid.  The synthesis of this 
material can be accomplished on an automated protein synthesizer, but it is 
going to take a very long time, and will require relatively large 
quantities of reagents.