Build a modern vintage car site for private individuals to sell cars

Assignment: Build a modern Swedish marketplace for vintage cars Hello! I am looking for a skilled and affordable web developer who can build a modern, professional and mobile-friendly Swedish marketplace for vintage cars. I want to use AI to keep the development cost as low as possible. The goal is to make it much easier for private individuals to sell vintage cars than on traditional classified sites. 1. Design and user experience * Modern and sleek design focused on vintage and classic vehicles. * Must work perfectly on mobile, tablet and desktop. * Fast, simple and easy-to-navigate website. * Start page with large vehicle images, a search function and featured listings. 2. Secure login with BankID * Users must be able to identify themselves with Swedish BankID. * Sellers must have a personal account where they manage their listings. * Possibility to edit, pause and delete listings. * Buyers must be able to contact sellers in a safe way. * The system must counteract fake accounts and fraud. I want you to propose the cheapest reputable solution for BankID and report all connection and transaction costs. 3. Automatic vehicle information via registration number The seller must be able to enter the vehicle's registration number. The website should then automatically retrieve available vehicle data from an approved data provider. Examples of information: * Make and model * Model year and first registration date * Fuel and technical vehicle data where available * Other relevant vehicle data that the service allows us to use. The data should be filled in automatically in the listing form. The seller must be able to check and correct data that needs supplementing, especially for older vintage cars. 4. AI assistant for writing listings This is an important feature. The seller should be able to enter a few simple details, for example: "Volvo Amazon from 1967. Renovated engine, nice interior and some rust on one door." The AI should then be able to: * Write a professional and easy-to-read listing text in Swedish. * Create a clear headline. * Structure the information into description, condition, equipment and history. * Ask simple follow-up questions if information is missing. * Help the seller improve the text. * Never invent details about the car or hide defects that the seller has reported. The seller must always be able to review and approve the text before publication. 5. Simple listing publication * Upload multiple photos from mobile. * Enter price, mileage, condition, restoration history and other relevant information. * Choose whether the price is fixed or whether bids are welcome. * Preview the listing before publishing. * Manage all listings from one's account. 6. Search and filtering Buyers must be able to search by: * Make and model * Model year and year range * Price * Geographic area * Vehicle type and condition. The website should primarily focus on vintage cars but could preferably be expanded to classic motorcycles and other older vehicles. 7. Revenue model I want to start with free basic listings to attract sellers. Later, it should be possible to offer: * Premium listings that are more visible. * Listings shown at the top. * Possibly extra visibility for a limited time. 8. Technical solution and budget I want you to use ready-made components, AI tools and existing services to as large an extent as possible. I want: * A fixed price for a first working version. * Separate reporting of one-time costs and monthly costs. * Information about the cost of BankID, vehicle data and AI calls. * A solution where I own the domain, the administrator account and the website's data myself. * A clear description of which features are actually included. * A solution that can be expanded later without everything needing to be redone. My desired build budget is at most 3,000–5,000 SEK. If not all features fit within the budget, I want you to propose the cheapest working phased plan. Please feel free to send examples of previous projects and state what you can deliver within the budget.