Brussels vs Brabant Wallon?

house prices:
http://www.immotrace.be/marketTrends.cfm?CFID=439767&CFTOKEN=78923881

Rentals:
http://www.immoweb.be/fr/a-louer/article/prix-moyens-de-la-location-en-2...

You'll notice that some areas of Brabant Wallon are as expensive as Brussels, and some communes are about 1/2 what you'd pay in others.

I would have thought that the most important factor is how you value your time if commuting comes in to the equation.
I wouldn't want to save money on the cost of living only to spend half of it on transportation costs and to end up commuting for an hour each way each day into Brussels.

Other costs are very similar. It's only really housing that makes the big difference.

You do have to factor transport in to your costs, and that will depend on the commute and where you work.

On the whole, you get a lot more house for your money in BW than in Bxls. You certainly get a lot more land (i.e. garden) - particularly great if you have kids. And the further away you are, the cheaper it becomes.

Prices of other things are more or less the same except that, generally speaking, restaurants are cheaper. I get the impression that activities and sports are also cheaper.

Of course, you'll have to factor in transport costs but you can see the cost of a monthly ticket on the SNCB website (e.g. from Gembloux (my station) it's €124) and if you are on a Belgian contract it's likely your employer will compensate you with a tax free amount that covers most of this.

You should also be aware of travel times - closer is not necessarily quicker. If you come from Ottignies it's direct to Bxls (so only 22 minutes to Gare Lux. - it could take longer to get to the office if you lived in Bxls!) but anything closer to Bxls is an omnibus so slower.

It can be a bit tricky if you want a night out in Bxls (the trains back home are not particularly late) but that just takes some coordination.

I'd recommend it.