YES.
Have put anywhere from $50 cash to a $500 check in a sympathy card to either: A close friend/relative whose immediate relative has passed OR the family of a close friend/relative who has passed. Reason being there are usually expenses associated with a memorial service or special luncheon/dinner in honor of the deceased. Seems most people appreciate this, and I hope they would never consider it "tacky". I have also brought finger food, cookies, desserts, etc. to gatherings held at peoples' homes in honor of the deceased and/or to celebrate his/her life.
I have also sent sympathy cards - without any money - for casual coworkers and acquaintances (or their families) I don't know well.
I would think any respectful gesture of sympathy would be welcome and appreciated.