go with maxis if you need maxis one plan, if you want phone to be cheaper and force yourself to take maxis one plan, then you should consider buying ourright from apple malaysia store online

for maxis one plan you have 0 loss even you terminate before 24months contract finish

i make an example for you, iPhone 7+ 128GB RRP is RM4299, with MOP128, you pay RM2915(should be exclusive of GST) + 6* = RM3090, the total saving is RM1209
24 months contract, after you use 6 months, you terminate your contract, you need to pay maxis ~RM907 (contract termination before mature), so conclusion your phone price now become RM3090 + RM907 = RM3997

p/s: there are cheaper iPhone 7+ offer elsewhere, for example lazada, but be sure to buy from trusted seller like lazada sometime lazada RM300-500 cheaper than RRP