I hope that lala guarantee the safeness and privacy of their app because Ive read that the cheaper the method or cheaper the payment, it causes more risky for the customer.
I think the reason why they offer at lower price for all the method because they wanted that the client spent at low cost. They've patterned it like a Chinese in the business industry. They sell at lower price and more customer/s will buy rather than selling at higher price with limited customer. The more customer the higher the income.