So you pay for your own salvation?
Everyone in Purgatory is already saved, and they know it. What's happening in purgatory is two things required by god's justice: purification and atonement for the temporal effects of sin.
The purification is alluded to in 1 Corinthians 3:15 -- "... he shall suffer loss: but he himself shall be saved; yet so as by fire."
The atonement aspect is alluded to in Matthew 5:26 -- "... Verily I say unto thee, Thou shalt by no means come out thence, till thou hast paid the uttermost farthing."
Typo. That’s “God’s” justice. Capital “G”.