[evlatests] Hardware costs/Setting Levels

[Travis Newton]

Cost estimate for 3 channel phase invariant attenuator
with input isolation gain block for use in D30X module:
$850/module, with most expense coming from custom housing and SMA 
connectors.

Savings realized by removing output attenuators from T304:
$27/module

Savings realized by removing all but 8,16 dB bits of
output attenuators from T304:
$0

Savings realized by removing input attenuator from T304:
$240/module

tln