Day tours to Jigokudani Monkey Park (Nagano)

Hi! Does anyone know of sites that offer good (preferably cheap) tour packages that goes to Jigokudani Monkey Park in Nagano, coming from Tokyo? Day tours or overnight are okay. English or Japanese sites also okay...

So far I only know in Japanican, but I find it quite expensive since travel is by Shinkansen... I think if the tour travels by bus it would be cheaper?

Thanks for any info :)

Which date?
livin' Tokyo? or as tourist with visa?

Jigokudani Monkey Park access is not so hard.
Book Exp[high]way bus to (JR)Nagano stn cheaper than Shinkansen plan
but winter Exp[high(toll)]way often not safe by snow/ice.
By Shinkansen expensive exactly but really safe,fastest and comfortable.

If until JR Takasaki stn by Rapid(no need EXP fee) save Shinkansen EXP fee.
or until JR Matsumoto from Shinjuku by LtdExp Azusa/Super Azusa plan,too.
After Matsumoto by JR regular commuter train or LtdExp Shinano until JR Nagano.
(both LtdExp are not Shinkansen)http://www.hyperdia.com/en/

If you have the time, do stay overnight at say Yudanaka Shibu Onsen while visiting the Snow Monkey Park.