I haven’t heard of any really cheap group pilgrimage to Poland. For a pilgrimage from the US, a big part of the cost is airfare, so you have to allow for that. In the summer, the airfare is always higher, as much as $1600 from the west coast, less from Chicago or New York.
If you go on your own, you can stay at hostels. In summer, most universities rent dorm rooms to tourists. Sometimes they will do this during the school season, but it’s very limited. If you went to Krakow, you could take a train to Czestochowa and then call a cab or walk (it’s a long walk but still possible if you’re in good shape) from the train station. From Krakow you could also take a tram to the Divine Mercy Sanctuary and then walk maybe about a half a mile (it’s kind of an incline so like walking uphill), or you could take a taxi. Also, there is lodging right on the sanctuary grounds - kind of priced in between a reasonable hotel and a hostel. It’s really not far out of old town Krakow. Another lesser known pilgrimage site that is worth seeing is Kalwaria Zebrzydowska.
There are also private guides available for hire who could take you to places you wanted to go and who also act as tour guides. Some of these can be tailored to your liking. It is also possible to find companies that offer tours to certain places, for example, you could get a bus tour that would take whoever signed up that day to Czestochowa, for example. These tours are not a pilgrimage as such, though, and from I saw, the tours are more secular oriented.
If you do not speak Polish at all, it will mostly not be a problem in a large city like Krakow or Warsaw, as tourist-oriented places usually have an English speaker available and many young people have studied English. The only place I encountered difficulty was outside the big cities and in the train station, but if you buy the train ticket from a travel agency office in town, someone there usually speaks English.
