Is there a simple, safe and low cost way to implement a (limited) database to be outside (close) IT control? This question is a spin off of the discussion here (What are the risks of building a database outside IT control?).

Background: I'm a risk guy that builds little betas, mostly in Excel-VBA. I have a lot of freedom in this 'beta mode'. People ask me things, I build it, they test, it crashes, I fix, it crashes, we change the specs, I rebuild it, they start using in a daily basis, it crashes, I fix it, specs, rebuild, etc..,etc. Lots of betas don't work and we just let it go. For the surviving ones, one sunny day we all realize the whole thing is stable enough, its minimally documented, and they put in a list that one day one real programmer will integrate into some new ideal system to come.

I realize this is problematic for IT (and really for everybody in the end) and that's one of the reason I want to start building simple SQL databases which make the whole thing way less messy then a db hidden in a branch of excel files.

Now, my IT tells me its policy, as in many places, that mortal user like me should not build dbs.

My question is: What's the set up I can offer that is simple, safe and low cost to implement from IT perspective? One idea is just to put it in a separate PC but I do need people in the network to be able to get data for the beta thing to work. Otherwise it can be confined to the hard drive.
Here's my view of the situation:

The data you are working with already have a source; they are extracted from some data mart or "system of record" and given to you, probably as a CSV file or something, which you load into Excel and build your models. Subsequently, there is already a database that has the data you need. Further, there is probably a bunch of development and QA (that is, non-production) versions of this database, to which it is much easier to get access. 

If that is so, your best chance would be to discover where your data are coming from (if you don't already know) and ask your IT to give you access to a development copy of that database. Since they already maintain it, there won't be much extra effort required on their side and they might be less reluctant to help you.