Prices of various parts taken off of the web sites of Digikey and Futurlec
(I've sampled all my semiconductors, so they haven't cost me anything)



If you wanted to build my EEG system:

------------------------------------------------
Analog section
--------------
INA114    $7.90 Futurlec
AD8605    $1.68 Digikey
MAX7401   $2.65 Digikey
TL062     $0.25 Futurlec
------------------------------------------------
Digital section
---------------
PIC12f675 $1.90 @Futurlec, $1.93 @Digikey
78L05     $0.20 Futurlec
TLE2426   $1.30 Digikey
PC817     $0.15 Futurlec (need 2)
DSUBPCF9  $0.55 Futurlec
4xAA Battery Holder:  $0.30 Futurlec
------------------------------------------------
various resistors and capacitors (price unknown)
------------------------------------------------


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Various parts that I have priced:

Instrumentation Amps
INA114      7.90 Futurlec, 8.40 Digikey (5.25/1000)
INA128U     9.40 Digikey
INA128UA    5.80 Digikey
LT1168      3.70/1000 (Linear's listed price)
AD8553      2.26/250, 1.64/3000 Digikey

Op Amps
TL062       0.25 Futurlec
TLC277      1.78 Digikey
OPA277U     2.03 Digikey
AD8605      1.68 Digikey

Filters
MAX296      4.43 Digikey
MAX7401     1.98 in 1k quantities, $2.65 Digikey

Power supply / Voltage reference
78L05       0.20 Futurlec
TL431       0.35 Futurlec
TLE2426CLP  1.30 Digikey

Digital stuff
PIC12f675   1.90 Futurlec, 1.93 Digikey
MAX232N     1.50 Futurlec, 0.90 Digikey
MAX232DR     .85 Futurlec

Hardware
4xAA Battery Holder  $0.30 Futurlec
DSUBPCF9             $0.55 Futurlec