Fiinding an Installer

My sink disposal leaked.  Not a massive surge, but enough to leave a small puddle in the tub under the sink.  Can it be repaired?  Should it be repaired?  From an online search that instantly directs me to somebody experienced at this, a bottom leak usually requires replacement.  From a practical standpoint, I've had the device for decades, replacing it once, maybe twice, in the forty years I've lived in my house. A new unit with all the advancements in technology over the time since I last bought one costs under $200.  From that viewpoint a disposal is disposable.  

At Kakiat Junior High School the NY State Board of Regents compelled the boys to take wood shop one year and metal shop the second year.  Plumbing was not in the mandatory curriculum, or even offered in the later years to the kids directed to the academic curriculum.  Knowing this would have saved me some money over the years though far less than I was able to earn as a doctor.  Fair exchange.  I handle the prescriptions, somebody else installs the new disposal unit.  All I need to do is find somebody who knows how to do this and agree to a price.  Finding somebody is easy.  Determining a price has not been, even in this computerized age that has the big box home stores offering installation and several popular Home Advisor type sites matching homeowners with contractors.  I would think that this would be a straightforward project for any plumber who has an inkling of how long it takes and what might go wrong.  If periodontists can give an upfront price for an implant, I would expect a plumber to be able to offer an estimate for a common installation.  The Angi's List and the Home Depot not being helpful at all in getting this relatively minor project to completion, that leaves me to call a few plumbers on my own and see what they charge, then pick one.  Or go to the YouTube Videos on how to install a sink disposal and learn the skills that the NY State Board of Regents neglected.