If you have to buy someone a gift for under $20 what would it be? Sometimes doing Secret Santa at your job can be stressful if the person you picked doesn't have anything specific on their list. Make it easy for them and write down 3 things that is easy to get. If you have a maximum of $20 on your list then don't put a shirt or blouse down. Not everyone has your taste and you might be getting a gift you really don't like.
Every year I put lottery scratchoffs as number#1(I won $10 from my co-worker in the past and plus your secret santa can buy those anywhere)
Then I put candles(this make it less stressful for them to buy you something and plus)
Last but not least I put down giftcards. You can buy giftcards from anywhere.
If someone picks me they can never go wrong because everything I wrote on the list is simple. If you are going to do secret santa make sure you don't make it hard on the person that picks your name. :)