OPINIONS SOUGHT - Do I Upgrade to 64 bit?

[newtusmaximus]

Terminal : Free readout
inuxlite@linuxlite-HP-Compaq-dc7700p-Ultra-slim-Desktop:~$
linuxlite@linuxlite-HP-Compaq-dc7700p-Ultra-slim-Desktop:~$ free
            total      used      free    shared    buffers    cached
Mem:      3094220    1245376    1848844      48432      96776    845920
-/+ buffers/cache:    302680    2791540
Swap:      3135484          0    3135484
linuxlite@linuxlite-HP-Compaq-dc7700p-Ultra-slim-Desktop:~$

Running LL2.8 32bit 3 GB RAM  (3 x 1 GB)  Standard config;  LAN connected.  Intel Dual core 6300 CPU  1.86 GHz

CPU capable of 64 bit - Maximum RAM  ( Bios) 3 x 2GB.  Video card  shares existing memory

Standard office use - Not gamer.  Some video viewing.  SKYPE

QUESTION

With Ubuntu threatening 32 bit demise what are my most cost effective options?
a) changing to 64 bit , utilising existing RAM -  will I run into  low memory availability issues.
b) Bite the bullet and buy 3 x 2gb sticks RAM (Ebay)

Option b) is virtually the same cost as the residual value of the HP DC7700p 

TIA.