Car is slow to start and then goes in and out

My girlfriend just bought a 2001 Toyota Camry with 87,000 miles on it. The car sometimes won’t start right away when she tries it in the morning. It usually takes a few tries and this morning once she got it started, the power went in and out for a few blocks and then it was fine. The battery light isn’t lit up. We’ve had the battery checked and the mechanic said it was fine and should start her up for at least six months. When we first bought the car it started on the dime and other than these startup problems it runs like a dream. The previous owner did tell us, however, that it was used very infrequently for the past year. Why is it having trouble starting every morning and how much is it gonna cost us to fix the problem? Thanks!

It’s that simple, isn’t it…name a couple of symptoms and the solution just pops out?
Perform the scheduled (by the car maker) routine maintenance; then, see what’s what. Some of those maintenance items are: air and fuel filters, spark plugs, fluids, etc. (check the schedule).