Is UOB SmartPay worth it?

I am considering using UOB Smartpay to split up my payments into installments.
It's not that I do not have the cash, just that I do not want to pay such a big lump sum amount at one shot.

However, it comes with a fee, and for 12 months the fee is 5%. If the amount is $20000 the fee would be $1000, which would be a considerable amount.

Should I use the UOB Smartpay to split up the payments but end up paying more, or just pay the lump sum and end up with less money in my bank account?