You can use different addresses to receive each time. The only problem with fees comes in the form of hsving to pay higher fees you you want to make a larger purchase than one of your inputs. It might be wise to consolidate your inputs (send all your funds to a single address in a single transaction in order to avoid this - when fees are low too).

There are many receive addresses to support airgapping, invoices and privacy. If you care about the latter you can also just use the "receive" option.