That price will be old hat by now and there are many companies that will sell you the device but you obviously cannot get from the manufacturer.
Looking at both data sheets on the 3430 and 3630 they are identical pin out wise and size wise, if i look deeper into this then hell its worth a try given the fact you got a 3630 in your hands as it will only take seconds to swap. And all the data will be in the right places thats for sure so it is only a matter of trying and see.