My take on this would be this: first, determine how many people would be in this society. Then, determine how often you would collectively want to brew.
Based on your question on cost for a system that "would be appropriate for a uni society," I'm assuming this setup would be for collective use and you'd want to get regular brews going. As an appreciation society, I would suggest to dive in to all grain brewing right off the bat. It's more "traditional" so your society would get a better appreciation for the trade, it is more cost-effective per batch, it truly isn't as daunting as some make it sound (I switched from extract after my first batch with only slightly more reading), and dammit, your brew day is about 1.5 hours longer so that's 1.5 more hours of drinking time.
To support this idea, here would be my list and approximate cost:
Igloo cooler "homemade" mashtun (easily assembled with instructions from this forum): $60
7 gallon aluminum boil kettle (some will tell you stainless is far superior and aluminum won't work. Superior, maybe. Only route no way. And aluminum is much cheaper): $40 often less
3 fermenting vessels (buckets and Better Bottles would be my choice, and 3 so you can get a rotation going): $75
Bottling bucket: $25
Hydrometer: $7
Thermometer: $5
Wine thief: $10
Auto-siphon with racking cane: $15
Mash paddle: $10
Turkey frier propane burner (you could get a much better burner, but something simple like this works well): $30
StarSan (for sanitizing everything): $15
Funnel: $10
Bottle capper: $15
TOTAL INVESTMENT: $400
The starter kits bbeckwith is referring to really give you the bare minimum, but many of the things you'd want to support a group just wouldn't be included (multiple fermentors for example, wine thief, starsan, etc). You could go that route if you are unsure of support, but I promise you will be purchasing the rest after batch one. But if you are only interested in doing stovetop extract batches, and never more than one brew every five weeks, it is possible to get everything you need for under $150.
You could knock off $60 by going with extract batches and not putting together a mash tun, but you'd make that difference up in ingredient costs within the first 4-5 batches.
I'm assuming you'll have at least 5 people in your group and probably closer to 10. $40 bucks a head for an all-access pass to a solid setup ain't half bad.
My take anyways.
Ingredients per batch cost around $15-$20 per 5 gallons (for a "typical" strength brew" for AG and $30-$40 for extract. (this cost can be driven down based on bulk hop, bulk grain, and yeast recycling, but I figured I'd give a "startup" cost. 5 gallons will yield approx 50 bottles of beer.
This sounds like a great idea!