The Haunted Fun House foundation requires 60 Stone Blocks for the first part of the quest.
It will take 8 hours (and the 60 stone blocks) to 'hammer' the foundation.
For the second part of the quest, you do not need to spend any Silver Coins. Placing giftedForeboding Tombstones will count towards your total, and you can store them back in your inventory afterwards. It is therefore possible to complete this part of the quest by simply placing one tombstone ten times.