Bais Shamai says you must pay more for the olas reiya, at least 2 maah, since it is totally for Hashem then the Shalmei chagiga which is 1 maah as it is only partially for Hashem. Bais Hillel says you must pay more for the Shalmei chagiga, at least 2 maah, since part must be given for Hashem and part for the owner where as for the olas reiya you can pay 1 maah as only Hashem gets it.

Chagiga 1:3

Olas which are not obligatory can be brought on Chol Hamoed. All olas must be brought from money that is not hekdesh. Shelamim can come from maaser sheni money.

The first korban chagia on Yom Tov must be brought from non-kodesh money, the second chagiga, Bais Shammai still say cannot be brought from hekesh money. Bais Hillel say that it could be brought from maaser sheni money.