Haha, no problem, I was already wondering if you got the wrong thread (;
I am aware you meant the 4th, but I don't know if I will be available that day.
May I know where you are from? Because beer in Germany is actually pretty cheap - at least compared to most of the rest of Europe...
Alright, I combined some information for you and everyone else who is interested.
Hostels:
# Some years ago I stayed at the
Meiniger City Hostel, it's central, easy to access and quite nice with friendly staff. You can get a dorm bed for about 17.00€ and lockers/luggage room.
From this hostel it's a 5-minute walk to the "Rudolfplatz" tram station where you can get a tram "15, to Ubierring" and 11 minutes later you get off at "Ubierring", walk some hundred metres along the Bayernstraße and voilà, arrive in front of the venue (make it 20 minutes altogether).
# Another one would be the
A&O Hostel Köln Neumarkt, not far from the one mentioned before, about 22.00€ per night. From "Neumarkt" station you can get the "16, to Sürth/Bad Godesberg" and hop off at "Ubierring" 11 minutes later (see, takes about the same time as from the other hostel).
# Last one I can think of now is the
Station Hostel, about 10 - 15 minutes walk from Cologne Cathedral/Main Station... they offer beds from 17.00€. You'd have to walk to the subway station inside of the Main Railway station, take the "16, to Sürth/Bad Godesberg" to get to "Ubierring" in 15 minutes and that'd be at least 30 minutes altogether.
Check the internet for more cheap accomodations, but stay away from places in Riehl, Niehl, Nippes, Sürth or wherever as they're quite far away from the city centre / the concert venue. Also, Deutz is quite close, but more expensive, because of the Messe Hall there.
Food:
I don't know what exactly you're looking for and to be honest, when I'm in Cologne Central I always struggle to find a good place to eat... but there seem to be quite a lot of reasonable places around Heumarkt and also along the Rhine.
Actually, the whole "heart of Cologne" has many places to offer, you just need to get away from the shopping streets. Sorry, I cannot really help you right now, but if you specify what exactly you have in mind, I could look into it.