User replaceable option for SME 309

Now that I am retired I am putting serious effort into playing and selling vinyl(averaging around 5 hours a day at least) and it is time to think about employing a cartridge with a user replaceable stylus. It will be mounted on a 20 year old SME 309. I believe cost(of cart and replacement stylus) and the ability to mate well with he arm is a bit more important than performance since the goal is primarily to determine condition. Thanks for the consideration. LS, Try Tone Records