Do you think picking up a used harry potter 10217 for $100 no box is worth picking up?

If complete, yeah.  Kind of a no-brainer really.

Yes. http://www.brickpicker.com/bpms/set.cfm?set=10217-1 Worth $200 according to BrickPicker data that is 2 months old, but looking at a few recent eBay sold listings, they go for $220+. GOGOGOGO!

I would get it. But check first if the set is complete.

ya i just talked to the guy and he said its complete. i never bought a used set before so what should i be lookin out for? its already built 

I would ask if there are minifigures and damaged parts.

Make sure complete instructions and all the minifigures (like MartinP said) are included.  Ask him if he still has the box - not required, but icing on the cake.

ok ill check everything out. he said he has all 3 instructions manual but no box . thanks guys =)

Having all minifigs and accessories is really important I think. Sounds like a great deal.

You also have to ask about stickers. People "forget" they are on the parts list. Not sure if this set has them, this is more general advice.

You also have to ask about stickers. People "forget" they are on the parts list. Not sure if this set has them, this is more general advice.

I always forget about the stickers. In some cases I do not put them on the set. Other times, I bought a set used and it does not have any stickers. If there were stickers to a set, and they are missing, I do not think that it would affect the value much, depending on what stickers are missing.

I would jump on it for sure. My wife wants this set really bad.

Considering my stash of this set, I am pretty sure it will do well. If all stickers, pieces and instructions are there then this is a no brainer.

i picked up the set. everything looks good from what I can tell. the guy i bought it from said all the stickers on already the set and the instructions and minifigs are clean. Only thing is i need to get some replacement windows which i can get them from brink link. cant wait to take this bad boy down and build it again =)