Eh,forget the 15-30mm 3.5/4.5,you won't get creative with it,you really would have limits,also,i wouldn't suggest the 28mm f 2.8,it all depends on what you want to use,if you want the best ultrawide lenses,then you could use a tokina 11-16mm (tho it's manual focus,and if you are on a budget,then get the 12-24,it's 400 dollars.),which is the best ultrawide lens for DX format DSLRs,and gives sharper images than high end lenses like the Nikkor 12-24 3.5/4.5 which costs something like 1200 dollars last time i checked, And surely the 28mm f 2.8 is nice,but it is nowhere compared to the 1.8 one,in the end,it's your call.