Old laptop CPUs are hard to use compared to desktop and server stuff. The only times I ever really see them replaced, be it from failure or upgrades, are in macbooks when things die there (though it tends to be GPUs for that one). I have not looked to see if they fit something popular out there that some kid on a forum somewhere discovered at this point though.
4 gigs of what? 2x2 gigs of DDR2 might be worth something of note as it is about as good as it got and 4 gigs can make a nice core2 thing quite usable, we have maybe just gone past that going from useful upgrade to someone that has a sort of legacy machine though and the price might drop a bit. DDR3, especially if it is 2 sticks of 2, is not worth nothing but it is mainly for those with awful laptops (I saw various netbooks ship with 1 gig of DDR3) that want a bit of a bump as 4 gigs is plenty usable for day to day stuff.
Second hand hard drives are a tricky one for me. SSDs even more so. 120 gigs is about as low as things go too. I would never buy anything more than a barely used one to resell to a customer. I might stick one in my own throwaway machine though. Alternatively you can buy a reasonable 256 gig SSD for $89 now
http://www.newegg.com/Product/Product.aspx?item=N82E16820226688
Disc drives. Little and less, less still if they are some custom bezel type. Maybe if they are really nice drives (full dual layer burners or blu ray readers or something) but if they are basic single layer or CDR and DVD ROM things then nope. They don't die so very often either and most people don't care any more.
Heatsink. It is a lump of material. Tends not to get broken or die unless by failure in repair somewhere, and that is a fairly spectacular failure to pull that off. Also tends not to be the most useful in general (I like to stick my peltier pads and other electronics that needs cooling to whatever I have to hand) or for other laptops owing to the custom and small nature of things.
Network card for laptops. If I am on wireless g and need say N from that card it is not impossible but generally few buy them for anything really. Low profile USB has pretty much taken that market.
Screen. Could be worth something as they do get broken. There are hundreds of different models out there so yours might be shared by something popular, chances are not great though. If you are lucky they might do a conversion kit for that screen model and you can have a nice desktop monitor out of the deal. You can try selling it somewhere someone would look for parts and wait until it gets sold. Were I running a general computer shop I would probably offer a pittance as they tend to only want to replace something specific, even if I had something in the back that needed replacing on I would still have to warranty it afterwards and some random screen that someone not me and flogging parts is selling is not a situation conducive to me being able to give a good one. If I pay $20 then I might never use it and that is $20 I won't get back, even if a customer wanders in and buys it from me they would probably be expecting to pay the usual $60 + fitting anyway. A particularly unscrupulous shop might pay the $20 and charge the normal $60 + fitting to a customer mind you.
If you are selling the whole screen assembly then I occasionally like having those when doing screen replacements if it means I do not have to mess around with screen bezels.
So yeah you probably have not a lot of note. If you managed to sell it all for ebay rates on ebay tomorrow (a very big ask, more likely you get to wait and (re)list things over months) you would do well to break $100 before fees with most of that being for the screen and SSD to an idiot, unless that is DDR2, in which case $100 is more reasonable. The only people to make money breaking laptops do it for new gear, high end systems, desirable systems or have a thousand ones torn apart and warehouse space to store it as they process individual orders.
For a local PC repair place you would be doing well to get more than about $40, maybe a bit more if they like the SSD. You walk into my shop I might buy the RAM if it is 2 gig sticks of DDR2 and offer a minute sum for the SSD but the rest I would not be interested in, unless I personally had that model of screen and wanted a spare for me.