Which store sells inexpensive Randoseru ?

Where can I buy less expensive Randoseru in Nagoya or Kyoto?
Which Department or Children store are least expensive? Is it possible to buy one for about 5,000 yen?
Is there a second hand shop for used Randoseru?
I will check Komehyo in Nagoya, but where else to look?
Thank You very much for your help!!!

Price of randoseru as new[新品] 30000 to over 50000Y usaul.
(more expensive one exist)

Sencond hand[中古] not a lot(now off season)
but some private traders post found.
http://jmty.jp/all/sale-kw-%E3%83%A9%E3%83%B3%E3%83%89%E3%82%BB%E3%83%...
Click title then jump to orenge button and click
will be open email form.(not need log-in)

Use google translate recommnend if you cannot read Japanese.

A quick check on amazon japan show fews randoseru ランドセル selling about 8000yen.

Randoseru of Nitori is about 20,000 yen.
It seems to have been designed to use six years.
http://www.nitori-net.jp/tokusyu/randoseru/lineup.html
http://www.nitorihd.co.jp/en/division/index.html#Nitori

Take a look at Amazon Japan. Averages seem to start at 7,000 - 8,000 and up, but there is this one for 2,800 (paste into the search box):

ワクワク通学ランドセルカバー　透明・クリアブラック　日本製　N4150200

FYI, that's for a randoseru cover, not the bag itself. As mentioned, they start at around 7000 yen online.

Thank You, will try Amazon.