Both my mares
My pony I actually leased for 8 years before I bought her. I always knew one day I would, but how it happened was a quick e-mail of "she's for sale, do you want her" and me phoning the owner up saying "YES" and then a few hours later driving to her house to sign the papers. It was a hectic day, and I felt like I was in a dream for at least a few months after - I mean, she is my heart horse and to actually legally own her is amazing.
My other mare I bought on a whim as well. I had been halfways searching off and on for 2-3 years, then came across her add when I had given up searching. Wasn't seriously looking. Her had gave little info and no pictures. She was MUCH larger than I was used to and I hadn't dealt with a horse so green in a few years. She was for a 2 day a week lease, had been backed 4 times. Something was telling me to contact the owner anyway. So I did, and I went to try her later that week, immediately fell in love and told her owner I'd love to lease her. A couple days later I get a phone call from the owner asking if I'd like to buy her. I said no, I was not in a position to buy her but really did want to lease her for that summer and then possibly consider a purchase. The next week I signed her papers
Somehow I just knew it was the right thing to do. I have owned that mare for 2 years now, we have had a few huge ups and downs, but I wouldn't trade her for the world.
Also, not on the topic of horses, my boyfriend owned a lovely 1980 ford f100. I was in love with this truck. Then our good friend's dad wanted to buy it. I, then and there, decided I had to buy that truck. So I did. 4 months later I sold it to the friend's dad.
Also not really a purchase, but kind of.. in October last year my cat had a freak accident and broke his leg. My only option was put him down or surgery. Anyone who knows me knows how in love with this cat I am (he was rescued by my best friend at 2 weeks old, and she didn't know what to do with him, and me being the experienced cat owner (on a whim) told her to drop him at my place ...at 2am) anyway. Without even thinking it over, I said yes to his surgery. 5 months later and I am SO glad I said yes to the surgery, and so is he. =)