I work for a small business as well and we looked into VDI a while back. Here's what I learned and I'll expand on a few of these points below.
- VDI needs scale to get a ROI.
- To do it correctly takes a large initial investment, especially in a small business which lacks some key infrastructure in most cases.
- Not all jobs/applications lend themselves to virtualization.
- All desktops here have 2 monitors and thin clients that support this aren't much cheaper than a desktop.
Scale and Startup Cost
You can do it on a small scale and on a tight budget but I don't think you'll be happy with the results. To do it correctly unfortunately takes quite a bit of upfront capital investment that at a small scale that we didn't think yielded a very good ROI.
From the software side of things you'll want to invest in VDI management tools to deal with vm provisioning, connection brokering, and remote desktop protocols that support multimedia acceleration. These deal with spinning up and managing new virtual machines, managing patching, and balancing the load on the physical hardware. Normally these things are packaged together but they can be split up and purchased separately if you don't like the offerings from a single vendor.
On the hardware side of things you need to consider that you're not only consolidating processing power, which is cheap and plentiful these days, but also IO which is not cheap and plentiful. Also a single point of failure poses a larger risk to the operations of the company so you need to try to minimize that risk a bit. This all means you need to have multiple servers with a proper NAS or SAN storage environment to run this on.
For the thin clients you can get by with using the existing desktops rather than dedicated thin clients but now you're managing the VDI and the desktops. If you lock down the desktops good then that shouldn't be too much overhead. So that's doable. But if you go the thin client route then that's going to take some more up front capital but they should last longer than a desktop.
How much all this costs really depends on what infrastructure you already have in place. But most small businesses don't have the proper infrastructure.
Things are improving but if your expectations are to have the same experience and capabilities of sitting at a physical desktop then you'll likely be disappointed with the current state of VDI. It's getting better and it current can deal with office type apps where you're mostly dealing with text pretty well. Multimedia is still a bit troublesome though. There are some commercial remote desktop protocols that attempt to address/accelerate this and I found that they do help. However the primary roadblock we ran into was the fact that the majority of our desktops are used for engineering apps for PCB design, Electrical, and Mechanical Engineering which rely on hardware 3d acceleration (OpenGL) don't work well or at all in some cases. I think some of the PCoIP stuff that's coming out now may fix these current issues but it's still relatively new and expensive.