Front end problem resulting in abnormal tire wear

Three months ago I replaced both front tires. The old tires were worn mostly on the outsides. I immediately noticed the same thing happening with the new tires. After only three months of driving at most seventy five to one hundred miles a week, the tread on both front tires appear new on the inside and completely worn out on the outsides(metal and threads-hardly any rubber left). Someone suggested that there were bushings that needed replacing-that it would not help to align the front end. They also said that old car parts are hard to find etc. My problem is that I am on a fixed income and would like to try to keep this little car going as long as I can. It is a five speed and gets forty mpg. Do you know what these (bushings) are (if you think this is the cause)? If so, do you know where they might be available? And # 3, is it a hard job? (Would it be too expensive?) You have to weigh everything in when it comes to maintaining an old vehicle! I once owned a 1968 Jeepster Commando convertable. Parts were hard to find, and expensive but totally worth it! What a cool car! This car on the otherhand is just an old car to get me from point A to point B (sometimes, when I am having a good day!) Thanks so much for your help. Sincerely, Pam Lund