If you want to maintain your mower then JD produce a Technical Manual for your mower, about 200 pages worth, very comprehensive, easy to read with explainations and testing proceedures as well as showing where all the electrical bits go.
However if you expect to get great value items for nothing you are going to be dissapointed as JD charge a fair & reasonable price for the amount of work that went into making it.
They can be ordered directly on line as a download or CD .
Alternatively you can buy them as printed paper from your friendly JD dealer.
As for "overpriced" what they really are is a fair & proper price.
JD can do this because they are big enough not to be blackmailed by the retail giants into providing their parts at cost to Wally, Lowes , HF etc etc on a credit , pay 30 days after sold basis like most of the other mower companies are forced to do now days because they have all gone down the high volume low profit margin route and are now at the mercy of the retailers who will happily sent the factory bankrupt as what happened to Murray .
They are also higher priced because usually they are of a higher quality.
I am not a JD dealer nor in any way connected to JD . I am an independent mower technician so buy & fit a lot of parts and when you do this you see the difference.
Now if your financial situation is so bad you can not afford the extra few dollars for genuine pars then go to the Stens , Oregon, Prime Line & Rotary web pages and search using your model number.
IT should bring up all of the parts that they stock for your mower .
Go to the Briggs web page and type in your full engine number, that is the model type & code numbers.
If you do not understand them there are instructions on the briggs web page.
Then download your IPL
Find the B & S part number , pop that into your google search and you will get thousands of hits