There are a lot of small engineering firms who make a good business doing work for people like you. I occasionally do that sort of work on the side myself, though not so much recently. It’s not uncommon for someone to walk in and basically say here, attach this (drops clock radio on the desk) to this (drops coffee pot beside it). The engineering firm then goes off and designs something exactly like that. You don’t need the expertise yourself. Just “outsource” your engineering.
Most newbie inventor folks have no idea of the engineering costs involved. People are surprised to find that to produce the first prototype “clock pot radio” costs them a good $50k. Sure, then you can build them for $8 each in china, but there’s a lot of design, prototyping, and setup costs involved up front.
By the time you add in marketing costs, overhead costs, shipping costs, and the bizillion other costs that go into running a business, you’ll find that you probably couldn’t afford to buy the Sony clock radio and attach it to Mr Coffee anyway. It would cost too much to produce it that way.
It’s also possible (sometimes) to buy the circuit boards out of the Sony clock from Sony and the coffee pot parts from the Mr Coffee folks, then integrate them together in your own plastic shell with your own private name on them. You’ve still got the engineering and setup costs for the plastic shell, and you still have the manufacturing costs of final assembly, but sometimes you can make a decent profit this way. Things that are expensive and produced in low volume are sometimes built this way.