Verb conjugation of "beitreten" in German

My first stop was great. I went there by myself not knowing anyone. I hired a room for two nights and walked around the city. After I had moved to my second stop for another two days something strange happened.
Anyway, once we arrived at the guest house the rules were explained: Washing my Jeans would be 2 dollars, a pair of socks 1 dollar and so on. I did not feel comfortable with these people.
The American (his name was Jeffrey) meant that this is the hour where usually the price of goods went down as the sellers were under pressure and did not want to return with the product.