Is that your website/domain? If it is, the first thing you NEED to do is to get control of the domain. It is currently registed to wisnet.com. They may have been doing you a "favor" when they set thing up. But, they are the ones that technically own the domain name. If you've been branding the name, you NEED to have them transfer it to you.
Next, what drives a site is content, content, content. Sure, spend some money on making it look good but it is important that the site be designed so that it is easy to update. You don't need to be spending money with your web designers each time you need to make a change. With that said, you may want to take a look at a Content Management System (CMS). These systems allow you to make content changes to a site through a central administration panel. Most CMS systems also provide a BBS that can be easily integrated with the site.
But, beware. Many CMS systems have known security flaws. Check them out first when considering a CMS script. This is one of the reasons that I have stopped using PHP-Nuke. There are others. But, the convenience may outway the risks for you.
You can also look at assembling components seperately. Start with a basic design, add in a News Script, a BBS and a Product/Ecommerce system. This can work well, but you create multiple points of administration. So, don't just look at the upfront costs. You also need to look at how much time you need to spend on maintaining and administering the site. Ask the admins here if the look forward to the chore.
I wouldn't worry about storage space or reqiuirements. Hosting accounts are cheap for storage and bandwidth. And, if you need more, your hosting provider will gladly sell you more.
The last thing I will add is create a regular backup procedure for the site. This is especially important if you have dynamic content. I run a job here (at home) on one of my Linux boxes that synchronizes the changes that have occured on my hosted sites every day. You NEED this type of belt-and-suspenders approach if you are using the site to generate income.
As for going rates, who knows? I think you should define what you need and then get quotes on a fixed price. I've seen prices quoted all over the place.
If you need any help, let me know. I can get to it as soon as I am done with the Agents sites.