Annoying as this may be, can't give you a single number as depends on how you do it. Biggest variables are flights and hotel. I had Air Miles so my flight was cheap and my very decent hotel was around £70/night. Flights can be expensive so worth seeing what routes and dates are cheapest and you can obviously pay more or less on hotels depending on budget. Tickets were around £20-30 except for Boca where I had to go via an agency which cost $150. Once there, depending on the very variable exchange rate and whether you can access unofficial exchange rates (which is actually quite easy), it was very cheap. Vey good steak, chips and beer round the corner from my hotel was £12. Biggest pain is the admin; given the controls on match attendance unless you go with an agency and pay through the nose you need to become a member of the relevant club (generally around £10-15) in order to be able to buy a ticket. So I am now a member at River, Racing, San Lorenzo and Independiente (plus CNDF in Montevideo). It's all manageable but just takes a lot of time to register as a foreigner, get your membership number, then buy a ticket which often go on sale only a few days before and then load it to you membership. But I got to Deportivo Riestra, River, Racing, Argentinos Juniors, San Lorenzo,CNDF, Independiente and Boca with broadly no hassle at all. 10 days watching footie in the sun, eating steak and drinking red wine or beer was not a bad way to spend a week and a half!