Greetings
My name is Kutas Gábor, and I'm a professional BIM developer, mainly focusing on 3rd. party archicad objects. Please see my portfolio for a glimpse of my skills. If you could provide more information about a the project scope, maybe some examples, I could make a detailed proposal of time, and costs. The development time is highly dependent on the complexity of the objects, on the needed functions, (2D details, 3D model, parametrics, User interface, listing), and on the necessity of native development.
In the past I've developed numerous items and libraries of the specified object types.
Please message me if interested.