Have you checked you local John Deere dealer or similar places. The JD dealers around here usually have some used equipment in their inventory.

Some of the hardward stores that do equipment repair are another source. There are places that specialize in lawn equipment

Ebay, newpaper ads, etc are an other source

Have you google JD lawn mower in the city you live. This usually turns up a few.

I see small used JD riders on craigslist all the time, and some look like they are in real good shape. the prices are from $800 to $t500 dollars.

I would not worry about the model year as much as I would condition.

I would look for a LX model (top of the small rider mower line) and i would look for 1997 to 2000.

My son-in-law has an old late 1960's model 111 that he used for years before he had to fix anything, and he stills mows with it.