The just hotel price for ChingLong Hotel and CiFu Hotel in PanYu is HK$780 and HK$480 respectively without breakfast + surcharge on Sat, may be $100 to $200.
I think the cheapest solution going to PanYu is
by coach + CiFu Hotel + by coach. We can have Chinese breakfast at CiFu restaurant. Taking a coach direct from HK to CiFu is more safe as they do not allow people in ShenZhen to got on the coach. Coach is $100 per journey while jetfoil is around $135 per journey per person+ taxi to the hotel.