Quite possibly. Atleast they've been honest and not tried to just sell you a battery. When the amps is low thsts not a problem. Its when the voltage is down, that's when you have a problem.
Check the condition of the bushes and other components, have the tracking checked. You want to be aiming for 0.5-1 degree toe in. If it's set at zero or toeing out it will give that flighty feeling.
The sickening thing is. I watched one of these go through the local auctions once. 70k kms, no rust at all. Hammer price was £968. Was around 4 years back lol.