yeah... like i mentioned i just picked up a set for $46.
and trust me when i say its not difficult to do it. actually it's a lot of fun to do some painting when you know you can't mess up. the result you can get from taking something that is plain jane and turn it into something that looks 100 times better really gives you a warm and fuzzy! lol
to do those necas (assuming you don't have an air brush) simply get a can of krylon white enamel... i think supermax is the new fusion brand which works well with plastics as it has adhesion promoter already added in. also get one of the panel line markers and a $1 bottle of black acrylic from michaels. just wipe the figures down real good w/ rubbing alcohol and wear gloves. then just paint them with a ton of light coats of white. take your time and let it dry, moving the arms/legs around after dry to get all the parts covered. if you can pop off the head its a bonus. just give it a good covering of paint, but do it in small coats so no running. let it fully cure for several days. now you've got a good solid base and you can build up the detail and panel lining. start with a paint brush and use the acrylic black. this will allow you to do the washes to get the details like holes and nicks in his shell, darkened areas on the mask, inside of the shell etc. you just add a little water to some black acrylic and dab the areas... let it dry... then swipe the surface clean w/ a dampened cotton swab and the paint is left down in the details. easy way to do detail work. do that to areas that need it, then finish the panel lines and detail lines w/ your pen. hit it w/ a coat of clear if you really feel the need (not necessary if you aren't subjecting them to crazy handling) and boom... all done!
the nice thing w/ the enamel base is the acrylic will wipe clean off of it w/ water if you make mistakes. seems crazy when you do it and looks like a disaster!! i've been detailing out my battle shells to give them a more artistic look. you should see how crappy they look until you remove the paint! literally the entire front of his shell was black... until i used the swab to clean it all off and leave all the details behind. hope all that helps!