Option #3/4: In a software project, you have three main levers - time, quality and cost. Improve one, then you need to lose on one or both of the others.<p>If you want real ballpark to start the thinking process (can't really promise much more than that without a lot more information) - well I'd say that a local 2-3 man shop might quote around $25k on this (i.e. ~4 weeks work).<p>Course, people will tell you that this is 1 week's work, or 2 days, or whatever, but generally this will be coming a developer, and they'll only quote the development time.<p>This cost will vary greatly depending on location (e.g. India vs Bay Area vs elsewhere). You could look at going somewhere like India, China or the former Eastern Block for development - the daily rate will be lower, but I suspect the overheads will swamp you, particularly for a one-off piece of work.<p>The approach will make a big difference too - I suspect you'd find if you tweaked certain requirements something like Google Checkout could provide a lot.<p>If you wanted to build something to demonstration level only, then probably half that.<p>A larger professional development shop could easily quote 50-100k. They'll want to do requirements, testing, etc, etc.<p>If I was building this in/for a corporate environment with all the trimmings, then I'd push this ballpack up to 100-200k. (You don't really get "Hello World" in this environment for less than 100k - but it'll be tested to the n'th degree, scalable, fault tolerant, etc, etc).<p>There are other costs as well, perhaps more significant and something to be aware of.<p>1. How much interface/web design do you want to put into the product? You can spend very little through to astronomical amounts on the design.<p>2. If you're handling images, potentially large ones, then you're going to have a much higher bandwidth and storage requirements than many web apps.<p>2B. If you need to scale (i.e. X new users every day) the you'll need to accommodate that. Even if you're not paying for the capacity, building in the ability to scale can be expensive. This could be anything from using a top-tier host, or investing a lot more in development and performance testing.<p>3. You might need other things like domains, secure certificates, company formation fees, legal fees (disclaimers, etc). You might (and I usually recommend) want a good copywriter. These things are usually pretty manageable in themselves, but add up really quickly.