Buy it!
I bought a 14SB at auction in 1994 for $100 (retail was close to $900 at the time), and I still have it today. It starts on the 1st to 2nd pull EVERY time, it runs as well today as it did then, and I wouldn't sell it for $1000 - it's that good of a mower! I use it each week for about 7 months of the season (roughly 28 mows per year).
Parts are still available through John Deere, but I find what I need from NOS (new old stock) from sellers online for a lot less $$. The only things I have really had to replace are the following:
- oil each season (buy 30W JD oil at Lowes or HD)
- spark plug about every three to four years (a few bucks at most)
- rear wheels every 1-2 years; they can be found online new aftermarket and used from folks parting out old mowers (rotate the worn out rears to the front during this maintenance item)
- oil/grease for axles, bearings, cables, etc.
- blade about every season since I live in a sandy soil area and the sand chews up blades
- check the valve adjustment at the start of each season too...
What big items have I had to replace over the years?
- carburetor 2 years ago - went with the OEM Kawasaki carb off eBay for $90
- I put a blade brake clutch in as a maintenance item 2 year ago as well - had not failed, but had started slipping after about 30 years of service (my mower is a 1991 model)
The mower runs is rock solid with an aluminum deck that doesn't rot to hell like steel, it's easy to work on, and it cuts beautifully. I wouldn't sell it for $900 today. BUY IT!