as others have said, big purchase is relative......do you have something expensive you'd like to save for? one time I knew I had some money coming in (bonuses, gifts) and I decided to put it all together to get a good watch.
What do you want?
I wouldn't blow it on costume jewelry but on the other hand, I have some 14K earrings that are now dated.
So if you're going to spend a lot, I'd try to get something classic like diamond studs.
I'm considering buying a bangle from Boucheron, however, it would be the most I have ever spent on myself