Manhattan Prep GMAT books: Set of 13 books in New Upper Changi Road, East Singapore for sale

Manhattan Prep GMAT books: Set of 13 books

Hi I have the following books for sale
1) GMAT OG Verbal 15th ED
2) GMAT OG Quant 15th ED
3) GMAT OG Review 15th ED
4) Manhattan GMAT 6th Ed Book 1-9
5) Manhattan Advanced Quant
All 13 books going at a bundle of SGD $500.