New budget Prius owner

Hey guys! New Prius owner, 2007 Touring with 178k miles. Bought for $2900 + $283 TN tax + $250 dealer fee = $3433. I'm a college kid, therefore the low budget.

The car was salvage title, rear end damage Copart lot # 37381019, bought repaired with rebuilt title from used car dealership.

I have a 1 hour 70 MPH commute, happy with the 48 MPG I'm getting so far. I've done all the electrical diagnostics that I can find to do (12V battery, dealership mode on screen, etc), and all looks good.

What do you think about price, additional things to check for mechanically or electronically? Is there any way to check the main battery capacity? It seems like it fills up really fast on regen. I do get 11.0 sec 0-60, so that seems good.

I'm also looking to get some speakers from Crutchfield, as this had no options such as nav, Bluetooth, JBL. Crutchfield recommended $190 JBLs.

Thanks