Say your pricing is based on a "mark-up" factor.
If C1 contains the cost and D1 contains the MSRP, then in E1 enter:
=IF(1.03*C1>D1,D1,1.03*C1)
where the 1.03 is your mark-up factor (modify this to meet your needs)..This says that if the marked-up price exceeds MSRP, use MSRP. Otherwise use the marked-up price.