You must have many coins in your piggy bank. Some put them in there to use in rainy day. While some just want to bank in them later. Please don't do any of the above before you check that coin. Your coin maybe will help you add up a bit of your money.
This is about Malaysia coin only. If not I need to write a few thousand pages for every coin in the world. Anyway, the concept is almost the same for any coin but please check standard catalogue for your country first.
1977 (mintage 10,609,162; UNC price=RM6) &
1982 (with extra "dot" on parliment house; UNC price=RM140).
For 10 sen, please don't ever missed 1971 coin because the mintage is only 32,326 and the price for UNC is around RM120.
1970 (mintage 1,054,000; UNC price=RM22),
1971 (mintage 9,958,000; UNC price=RM10),
1978 (mintage 6,847,000; UNC price=RM12) &
1994 (mintage 2,680,339; UNC price=RM45).
1969 (mintage 2,000,000; UNC price=RM150),
1979 (extra dot; UNC price=RM150), &
1995 (mintage 1,650,423; UNC price=RM20).
Don't forget to check for security thread for 1967, 1968 & 1969. The coin without the security thread is price around RM1,000 for UNC.