I share your dream. Just make sure you temper it with reality!
No disrespect meant, but if you're that new to sailing (as am I) how do you KNOW you're getting a "good deal" on a $5000 sailboat?
Another comment that peaked my eyebrow was the "ton of money" and then "15k". Purchase, maintenance, emergency fund, provisions, docking fees....I would't consider 15k a "ton of money", when spread out over such a period of time.
If you can pull it off, sounds like fun. Just caveat emptor when looking for a bargain boat to sail blue waters in! Check out some of the other threads here about those who encountered gales.....new rigging, sails, etc can set you back 5k easily.