I don't mind the budgets for secret santa, 5 are really nice challenges to make it the best possible, and 10/15/20 lets you get a really nice thoughtful gift and one in return.
I actually kind of prefer the 10/20 ones because I tend to put a too much thought into it, and with a fiver, try to get the most for my money, and in return I normally get the 'joke' style gifts or worse...forgotten.
For a higher budget, a combination of different things is good. I like to work on a theme, so previously I've made my own nando's gift set - a roasting dish(ceramic 70% sainsburys one), lots of nando's sauces and, jokingly, chicken (in the form of a rubber dog toy). You could do a night at the movies - netflix gift card, gourmet popcorn, sweets and fancy bowl.
Spa day, with a little towel, spa stuff and face masks.
Coffee or tea bundle - fancy coffee or tea, biscuits and a single serve coffee/tea cup - bodum do a cafeteria travel cup with two lids (one plunger one normal) or a tea strainer - like a metal tea bag you can put loose leaf in.
Bundling in tissue paper and cellophane also goes a little way in making something seem put together!