I started riding again the summer of 2012 with a Specialized Hard Rock MTB I picked up at a thrift store for $75. I put about the same amount into it and lost 30lbs over the summer of 2013.
Since then (thanks to ebay) I've added a 2011 Specialized Sirrus Hybrid, 2005 Specialized Allez compact frame road bike, and a 2002 Allez to the stable.
I'm semi-retired with a new career as an Author-Publisher with eight books (fiction) published online. I've lost a total of 61 lbs riding (18 of those twice). Good exercise for a fat ol' guy of 68. I do most of my own maintenance too, with the assistance of the wonderful people at Kawanis Club bicycle shop in Reno, NV.