"300 dpi and is sized at 450 by 450 pixels" this is the size I am using.

But some whole page scan of 20 chips at 300 dpi - at GoDaddy even with premium subscription - they complained and an endless notifications that my website is slowing the entire system. "More bytes pay more money" best money making, instead of "unlimited".

I took down several pages in the Let's Trade section, now they are happy.