Normally, the bridegroom's side will give a certain number of tables to the bride's side. For eg, 5. Then if the bride's side needs more, they will have to pay for the extra tables.The bride's parents will keep the ang pao from the given tables.
As for Pin Jin, the bridegroom's parent will discuss with the bride's parent beforehand. Normally, the bride's parents will return a portion of the pinjin.
As for jia zhuang, I don't understand why you have to buy yourself. Normally, the bride's parent will buy or they will ask you to buy yourself and pay back.