once a FOB or FOBIK is programmed on any vehicle, it can't be used on a different vehicle, the memory chip is in the FOB, under the battery, now if you had a new chip to put in there ..........
thats the way locksmiths can order them & reuse them
by the way, not all eBay sellers sell you used units, some have the brand new ones
LOCKSMITHS get theirs from most of the same places as Chrysler/Dodge get theirs & for cheaper prices & they can program them also
this is one such place that locksmiths use
each fobik from a locksmith cost around $140 without the emergency BLANK key, blank uncut emergency key is about $8
note: You are able to program 2010 DODGE RAM Remote key (FOBIK) by yourself if you have two working keys (or keys that start the vehicle). You can use the printed programming instructions that we send to make the key work for your vehicle. The instructions are very easy to understand and can be performed in less than a minute. If you only have one working key for 2010 DODGE RAM , the programming can only be done at the locksmith or dealership. This Remote key comes with New battery installed and is tested for functionality before sending.