The extra det is definitely more dps... however it's up to you whether that's worth it or not. The 7 det difference is probably all of 3-5 dps when you get right down to it. The most important stat for increasing your damage is weapon damage which is purely a function of item level. After that is STR. After THAT is determination at something like 1:5 between STR and Det. So by that ratio you could also look at those 7 points of Det as being 1.2 STR. Would you spend tens of millions of gil to gain 1.2 STR?