RKOWALK
I get my parts from these guys.
They are reliable, and priced right.
The only way you can get them much cheaper, is to find a wrecking yard that has an "S" model.
I bought a brand new car, ('06) and found it easy to justify the expense of "brand new" genuine Toyota parts because I know that one day I will want to sell my car, and with non-Toyota parts, you never know what you are getting. Remember, these are electrical parts, and poorly designed, or poorly manufactured crap can cause fires.
Something to think about the next time your wife and kids have the car out.
TRD Toyota/Scion Parts Accessories from Sparks Toyota/Scion
Even if the parts you want are not advertised, that's ok, just send them an email detailing exactly what you want.
They charged me $48 for the relay, and $125 for the switch.
Not too bad compared to what your dealer is attempting to overcharge you for.
Are you sure your dealer is not including the lamp assemblies too?