Does Magic Jammer negate spell cards cost effects?

[Burrow]

Sorry I probably phrased that wrong I'll make a scenario.

You play Premature Burial
pay 800 lp
but then your oppenant plays Magic Jammer
So Premature Burial didn't go through but do you still have to pay the 800 lp?

My friend says Magic jammer negates the spells effect but not the cost.
But what if to activate or even play the card you need to pay a cost?

I'm rather confused, can you help? :|

 

[masterwoo0]

"Cost Payments" can not be negated, no matter what generated the effect.  If a payment is made, and the effect card is later negated in a chain, then there is no refund of the cost.

To clarify, Premature Burial requires that you pay 800 life points to activate. If it is negated and/or destroyed in a chain to its activation, then you have already paid the cost to "turn it on" and cannot get your 800 life points back.