Your welcome
You'd need to let me know which map you require. Take a look at the Garmin website below and PM me with your chosen one. If its the one I think it is (pic attached showing some of the options) I have a price for you which I'll PM when you confirm. we can make large saving on the prices shown on site.
http://www.garmin.com/uk/maps/bluechart
When using the site above make sure you change option 2 to G2V for accurate info.
Do you want it on SD card ? SD card is most likely what you have now.
Regarding selling your current card. Put it upon here etc but it's market is obviously less than had it been a UK card etc.
Hope that helps
Peter @ Boatsandoutboards4sale ~
askboatsandoutboards4sale@sky.com ~ 07930 421007