Here's the deal. Atm my Iswara is like your Myvi. Hardly need to service. Like 7 months d since last service - running smoothly almost daily or every 2 days once until just about recently.

And say I do full "high mileage" service also, probably cost less than 2-3 months of your car installments and can last 1 full year (with multiple service intervals). This is why I prefer to maintain rather than buy new car. The expense of a new car is extreme for me. For the past 5 years, all i did was change the engine oil. That was literally all. Well, that and topping up radiator water every now and then.

Edit: Forgot I changed the tyres as well.... but those things lasted a good 10 years hehe. Used until become racing slicks then only change.