From what I can see from researching the Solara, it has TDI or Toyota Direct
Ignition. This system does eliminate the need for ignition leads from a
distributor, relying instead on a coil for each cylinder positioned close to
each spark-plug. This type of ignition system is not new. GM have used a
variant of this on their Buick V6s used in Holden cars here in Australia for
16 years without any major problems.  This is probably why they have quoted
$200 anticipating the need for one or more coil replacements if needed to
correct your engine's problems.

I would simply ask them what they base their quote on.

Jason