How much will it cost to develop a decent real estate website?

Like anything in life, if you pay crap you will get crap. If you want a website that will allow you and other agents to easily add/edit listings, feature listings, categorize listings, add tags with seo, a professional design, social media integration and a content management system, you'll want to hire a private developer. These people telling you to build a real estate website with godaddy's site builder are feeding you nonsense. You absolutely cannot create a real estate website with godaddy or any site builder. The real cost to hire a professional developer is in the thousands, normally under 10K but the price is dependent on complexity and the number of listings... well worth it and a negligible price when you consider a good website will ultimately result in more home sales. People are increasingly using the web to find properties, I know I found mine on zillow. I'd be happy to give you a free over-the-phone consultation. I am a professional developer and I have built real estate sites before. If you're interested, start a conversation with me on digital point.