Hi 
I just calculated how much my guys eat per week.
I had a good mealworm colony going until i used powdered milk in the substrate and it got to moist (don't know why).......ended up losing the entire container of babies overnight. My beetles are breeding again but it'll be a while before the colony is up and running so for now i'm buying lots of 500. I have 7 geckos and each eat about 10 mealworms per day. Times that by seven days and its 490 mealworms a week. I have read that its best to start out with 1000-2000 mealworms, probably gets things going faster, but for me it all started with 3 beetles that i didn't know what to do with. A few weeks later their container was full of baby mealworms.
LeoLover has by far the best care sheets for feeder insects.
The link to her site is in a responce she gave to the post PICTURE TIME posted by Rob Jenkins on Sept21 further down the page.
I use 9.6L containers for my mealworms but i have separated them into groups based on size and labelled for each gecko. 
Red 
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Crested Gecko Zeek:1.0
LEOS: Boo: 1.0 normal , Bronx & Nala: 1.1 blizzard,
Lily: 0.1 patternless, Abby: 0.1 albino, Zoe: 0.1 reduced pattern, Dot: 0.1 hypo
Chip: 1.0 papillion (small dog)
2.0 bettas