Need some confimation...Please advise

My mother's Buick Park Avenue ~1999 is getting to be hard to start. She has to crank it over about 4-5 times to get it going. It seems to try a few times, but it just sputters. I clean some corrosion off of the battery terminals, but it still does it. I'm now thinking starter, or maybe just a bad battery in general. Like I said, it does turn over each time.

Also, any advise on a cheap diagnostic computer that would work for several models of cars!?!?! We have a Jeep, Cobra, Grand Prix, and my mother has the Buick---The oldest is a 1997. Also, my brother and sister in-law have a Honda and a Chrysler minivan. Anything that would work on all of them and not cost a fortune? Any place on the web to get them cheap?

Please advise...Thanks

My mother's Buick Park Avenue ~1999 is getting to be hard to start. She has to crank it over about 4-5 times to get it going. It seems to try a few times, but it just sputters. I clean some corrosion off of the battery terminals, but it still does it. I'm now thinking starter, or maybe just a bad battery in general. Like I said, it does turn over each time.

Also, any advise on a cheap diagnostic computer that would work for several models of cars!?!?! We have a Jeep, Cobra, Grand Prix, and my mother has the Buick---The oldest is a 1997. Also, my brother and sister in-law have a Honda and a Chrysler minivan. Anything that would work on all of them and not cost a fortune? Any place on the web to get them cheap?

Please advise...Thanks

I would get the battery tested, most shops will test it for free in hopes that it will be bad and they can get money for replacing it. If it's not the battery it's pretty obviously the starter.

Mac tools sells one but i'm not sure exactly if you would call it cheap, but it will work on just about any domestic vehicle. Or you could get a Tech2 which would run you a pretty penny as well and you would have to keep it updated.... Good luck man

harbor frieght.com has one that just displays trouble code numbers and after 4 times it will erase code. It goes for around $40,