Most of the contracts are cheaper than the market value - scammers intend to let you think that you have a very good deal in front of you.
The upper part contains general information about the contract: type, issuer, status, location, etc.
Right below there are multiple lines stating who gets what. Everything you have to pay to the issuer of the contract is colored red - everything you get from the issuer is colored green.
In the example given above you are going to pay 450 million ISK and getting a PLEX.
WRONG! Look carefully:
You will pay 450 million ISK and you will get the PLEX as stated by the colored text "You Will Get/Pay". ADDITIONALLY you will pay a PLEX for the contract. So you get a PLEX from the contract and instantly paying 450 million ISK plus a PLEX totaling a loss of 450 million ISK.
Most capsuleers don't even look at the bottom part of the contract. Maybe some of the victims think that this is a summary of the contract in a list format. Don't be fooled by this! Better check twice. If in doubt, ask your friends/corp-mates/ally. Heck, don't even hesitate to ask questions in local.
The worst thing you can do is not to ask. There are no dumb questions, just dumb answers - remember that.