What do you enjoy most? Start upgrading there.
For example, yes, there's fun in having a good trip that's cheap, but there's a hidden luxury in spending more on travel:
Direct convenient flights/upgraded seats - you arrive faster, save time, and arrive at your destination more rested.
Better hotels - usually are in better locations, have nicer amenities, restaurants, services, views, vs. cheaper ones. If your hotel is $100 more, chances are it is closer to the places you are there to see, and you'll save an hour per day while on your vacation vs. staying out of the peak area
If it's food/cooking, upgrade your cuts, try the gourmet shops, get nicer knives and cookware.
Spending more willy-nilly isn't a smart way to go, but spending more on things you love to get back time and value, experiences, etc., almost always is worth it.