afaik, it has no monetary value if you use it to buy stuff... however in collectors POV.... naa nay value... remember... when US postal service made and error when they print inverted jenny... karon its one of sought after by philatelist and its quite expensive... my former boss owns a replication sa inverted jenny.. it worth almost a milliion pesos (price is in $)...
but first have it verified by BSP if that is indeed a misprint and not a reproduction... if possible request for a certification that it is indeed a misprint... and part of a batch release by BSP... in that way it will add more value on that money... since it is verified and has a documented certification..