If those are the two best days of boat ownership, then they used it all wrong!!
We went with a 17 year old boat, but one that had the engine replaced 2 years prior to us buying it thanks to a bad winterizing job. So while the outdrive showed its age and led me to replacing both bellows before ever putting it into the water, the boat has been amazingly reliable. We also paid less than $8k for it, with a trailer ('96 Chaparral 210 Sunesta). Only other real cost was having two cushions reupholstered, which was not particularly cheap either. The impeller on the water pump was also way overdue for being replaced, which I fortunately did before ever putting it into the water. I did all the work myself, except the reupholstery, thanks to how-to manuals and Youtube videos.
Ours is a deck boat (not a pontoon boat), which we really liked the layout better than the traditional bow rider / runabout. The seating is more open. Having two young daughters, the small on-board port-a-potty hatch has come in handy a few times too.
$15k definitely seems doable as long as you are patient. Being the start of summer, prices will be higher compared to fall when folks are facing another winter of storage costs / non-use. We bought ours in August and likely contributed to the lower cost. I would also do some research on brands. While not as easy to find reliable info as it is with cars, my understanding is Tahoe is at the very bottom, then Bayliner, and then a solid selection between Sea Ray, Chaparral, Regal, Crownline, Cobalt (ignoring the high end wakeboard lines).
Best of luck on your search. We have loved boat ownership and having the boat in the neighborhood marina, while expensive, means we use it way more often than if we had to hassle with trailering. Being able to share the boat by inviting other families out with us has also helped us to justify the costs involved.
