Amp repair cost — is this right?

That is highway robbery, depending which caps and size they use 
Nichicon super through would be near top of the line ,Nippon has a top series also ,as well as a few others , ask for a list of brand and cap uf sizes it sounds about $400 too high ,the quality was not that high to begin with buy something)NG else and rebuilt Thst 

Lots of uninformed opinions here....

Even before discussion that different caps would yield different costs and that design and layout are labor factors (I guarantee most here are not familiar with the 308s layout) people were barking out verdicts.

Just the choice of Caps will wildly change the price! You can buy caps that costs hundreds each if you choose!

The answer to your question is a firm... IT DEPENDS!

I can say from direct experience that I had an MF A5 integrated modded for about this price (with better caps, components and the results were stunning).

Please understand that there are a lot of people here who don’t understand that people need to make a living... If everything is done at or near cost... It’s called a hobby.

Sorry, thought I saw in a post that the repair shop was half hour.  I would still just put it on eBay for parts.  Maybe the shop can give you something for it

You can barely replace an internal fuse in a half hour!

Seriously?

I need to write a book of all cases that I have dealt with repair shops in the last 40 years. Here are just a few typical cases in my real life. A jumbo TV failed to turn on that costs $500 to replace a pair of $9 chips. Refrigerator company charges $260 to replace a $2 switch. It costs $500 to paint a corrosion furnace cap. Water softener company charges $500 to just dump the old salt and put a bag of salt that costs $15. A heating company charge $395 for a $25 heat sensor... and last but not least, a prominent high end company charges $900 to replace a 5-cent belt. They're all claims the values of "years of experience".
You're getting stuck with this service shop because you have spent $115 to ship your unit. If you want it back, you will need to pay at least $100 diagnostic fee plus $150 shipping and handling on top of your $115. Looking for another repair shop wont save you a considerable amount of money. The actual job to replace 8 capacitors is less than 30 minutes, and the cost of 8 capacitors is less than $100. The remaining is profit or "rip off" fee. Good news is you're not the first one or the last one. If you're really into the world of "high end", learn soldering technique and use
YouTube "how-to" video clips.