No, you checked it at the right time. Coolant level should be checked when the engine is cold. The level should be between the LOW and FULL level. When I fill to the middle of the two lines and then drive for a while, the reservoir level rises to the FULL mark (the level in the reservoir doesn't really matter as long as it doesn't get too far below the "LOW" line - it's the level in your radiator that counts)
General advice I hear regarding coolant : don't mix types.
That being said, the Subaru and Toyota coolant is the same for our car. When I bought it at my dealer (my reservoir was basically empty, needed some right away), it was $38 bucks, Amazon was $4 dollars cheaper, but now Amazon has it more expensive...
[ame="http://www.amazon.com/Genuine-Toyota-Fluid-00272-GTBC1-Coolant/dp/B00AKYP114/ref=sr_1_1?s=automotive&ie=UTF8&qid=1427089837&sr= 1-1&keywords=toyota+00272gtbc1"]Amazon.com: Genuine Toyota Fluid 00272-GTBC1 Blue Super Long Life Coolant - 1 Gallon: Automotive[/ame]
Price history:
http://camelcamelcamel.com/Genuine-T...uct/B00AKYP114
Toyota Part # 00272-GTBC1
Looks like Subaru's pricing is better than Toyota's.
Subaru Part # SOA868V9270
[ame="http://www.amazon.com/Genuine-Subaru-SOA868V9270-Super-Coolant/dp/B007NLOZAU/ref=pd_sbs_auto_4?ie=UTF8&refRID=0JM06Z9H90JNJ4YKR TSP"]Amazon.com: Genuine Subaru SOA868V9270 Super Coolant: Automotive[/ame]
Amazon Price history:
http://camelcamelcamel.com/Genuine-S...uct/B007NLOZAU
Subaru official pricing:
http://parts.subaru.com/p/Super-Cool...A868V9270.html