Sorry to break the truth to you - but this line of thinking is a bit naïve. Software (and software companies) has commercial value ($$) for one of two reasons: customers or IP. Since you don't have customers, and you don't have anything that appears to be patentable, it's going to be near impossible to sell this for more than $1.
That's overly simplistic. It's worth a lot more than $1, but unless someone wants to make a product out of it, the full source/server is probably not worth more than they'd pay for a copy of the software, and is arguably worth less, due to the maintenance burden.
Right now its value is in its potential for an aspiring product company. Unfortunately, without any customers at all, that's extremely hard to gauge, so it will require a steep discount. I'd probably pay at least a few thousand for it.
The realtors on your platform are your customers (and that's what provides value to a potential buyer). The contacts they have are their customers (and worthless to a potential buyer).