The first one if it's a 2011 model and an i7 model, it would be the 2.3GHz configuration. It's the top end model from Early 2011, is quad core and a very capable machine (I have one 😉)
The second one as it's a 2.4GHz model i5 with a GT 330M, means it's listed incorrectly. It would be a 2010 model and it's dual core. It is quite a bit slower than the former.
In terms of pricing, the first one is correct that it originally retailed for over $2000. The second however is the base 2010 model which retailed for $1600 (I think), so even with the supposed CS5 software (which by EULA license cannot be transferred since it's a student edition), it's still worth less.
The first one is a much better choice. In terms of what offers you can make, I cannot offer my opinion on that, simply just sellers on CL should not expect eBay-like sales on CL very often.