Its going to be a gamble no matter what we tell you to look at. The best thing would be if the seller could show you a big envelope stuffed with the repair receipts!
However, any Escort with over 100,000 miles on it -should- have had its timing belt replaced. In which event that would not be a problem again till 200,000 miles. You should have a look at the brake lines under the car, toward the back. The worst area for rusty brakes lines is right next to the gas tank, on the driver's side, ahead of the rear wheel well. You have to be able to look straight up though. Having a hand mirror and a flashlight would let you do this.
Ask about where the prior owner did their driving, in town, on the highway, and how long they owned it. If they havent owned it long, assume it was in-town driving; which is the hardest driving on the tranny.
If its an automatic transmission, the tranny might be the thing that would go out. So if the tranny has been replaced - then its likely $700 is a fine price. If it hasnt been replaced, be aware that tranny can go out long before it gets to 180,000. (By that distance its a good chance its been replaced, or that the owners used the car for long commutes: otherwise the car wouldnt be running anymore).
And understand that any 14 year old car is going to have things wearing out for the first time, not just due to the mileage, but due to the age. The list of things it could be is the list of the topics in the 2nd generation forum. If you do any of your own work, Escorts are great machines. If you have to have most all work done by a mechanic - then I hope you have a good reliable mechanic.
I have three 2nd generation Escorts. The first one (92) was given to me by a sister-in-law, with 192,000 miles on it. What it needed was a rebuilt tranny, and the usual maintenance items. I spent $1400 on parts, and since then its been a daily driver. The 2nd one was a 94 wagon w 98,000 miles that had dropped in inlet valve seat. It needed the engine rebuilt as well as a new clutch. I spent $1100, and since then its been a daily driver, with one trip to the west coast and back. The last one was a 91, with 187,000 that needed a rebuilt transmission, and the usual maintenance items. I paid $450 for it. I have spent $1300, & expect to keep it for dry weather use, as it has Zero Rust on it. An Arizona car. I do all of my own work, so the costs here were for the parts.
Good Luck.
P.S. If the owner wanted to sell parts off of it, & had a place where people could set out their tools and strip the parts - he could probably get $700 in a month or so after an ad on
www.craigslist.org.