So you buy 2 different rums. 1st being a higher end rum that you start off with, which should be enjoyed either neat or with 1 or 2 ice cubes.
The 2nd bottle, if you intend on continue to drink and don't care about taste could be the Sailor Jerry's or whatever lower cost.
I prefer something along the mid-range price wise. Usually I only have 1 or 2 drinks and I'm done. Just something to take the edge off and un-wind.
