Even if you ask people to bring a wine and cheese, you should have some wine for everyone to share. Start checking out your local liquor and wine shops. I once found a lovely South African red wine on clearance for $4 a bottle at a liquor store. I opened it, took a sip, and drove right back and bought all the bottles they had. You can luck out but need to be persistent.
I would have some heartier snacks - for example, one of my markets has smoked salmon pieces quite inexpensively, and they are nice for canapes or for dips -
Smoked Salmon Picnic Spread is just one example. This one is inexpensive to make and I found it good,
Simply Sardine Pate . There are other things with ham or other spreads. Pinwheels are nice and can be made with many types of fillings, for example,
Egg and Ham Pinwheels
Cheese spreads are more frugal than chunks of cheese and there are many posted.
Making canapes is generally more frugal than letting people make their own snacks.
This menu might give you some ideas of what types of things to consider
http://www.food.com/menu/wine-cheese-party-269