However, it's often better to work for free than for peanuts. The client who's paying you a few tens or hundreds of bucks will often treat you like garbage, AND give you poor feedback. Stick with your rate (if you don't have one, decide what you're "comfortable" charging... and triple it) and explicitly provide a "one-time discount" for the client to land on what they can pay. Clients treat you better the more "expensive" you seem — which seems to hold true even if they aren't actually being charged all that money.
I learned this early on in one of my side businesses: "The one who pays the least complains the most". Charge enough to communicate that you are a professional. Don't take clients who are low bidders. Let your competition take those and watch them suffer.