I have that bluray player as well. Got it for xmas from work.
I would buy a linksys
WRT54GS or similar off ebay or craigslist, flash it w/
dd-wrt and set it up as a wireless bridge. This is of course assuming you have wireless in your home. If not, you'd have to buy 2 wireless routers. The wiki I linked should pretty much spell out how you can do this. dd-wrt in my experience is MUCH more stable than the OEM firmware, and it has a ton of features. It's great stuff, and totally free.
There seems to be literally thousands of the WRT54GS routers floating around looking for a home, so you can probably find one for $20-$30. A lot of people poo-poo the ver 4+ routers because linksys gimped the RAM and flash mem on these later versions, but I have a WRT54GS ver 6.0 w/ dd-wrt micro as my main router and it works fine. You just have to flash the micro version of dd-wrt, which is missing a few features you probably don't need anyway (especially if you just need a wireless bridge).
If you don't have the LG bd300 hooked up to internet yet you may not know that there is a firmware upgrade available now that also lets you watch Youtube. The netflix functionality is pretty slick, we use it all the time. My only complaint is that it only lets you watch things already in your instant queue, you still need a PC to search & add content to your queue. Maybe a future furmware upgrade (cross fingers).
Good luck!