Should i mail or bring excess baggage when i fly back to america?

Im movin back to the united states from germany here in a couple weeks. ive been here since feb. when i came here i had only 2 suite cases. but as everyone know u accompolate stuff as time goes on. i am aware of the german '2 piece concept' meaning ur allowed 2 take 2 bags with u under 32kg ( 70 LBS). but i know for a fact i have more then that. sooo i thought ok ill get another bag. and according to airberlin ( airline i take to NYC) excess baggage 32kg and under cost an extra 25€ ( close to $25). but see i am traveling to SF. soo when i arrive in NYC i have to go thru costums, get my luggage check in at a ticket counter to get my next flight with virigin america.... im wondering if anybody had this problem. and whatr would be the cheapest way to get my stuff back home to reno ... i figured shipping thru mail might be better but it looks pretty expensive....and does anyone know the flt regulations with air berlin and virgin america... let me know