Re: FS Custom C6 445nm Blue 1.245W Laser for sale!! $155.00
Well, they are some of the best builders/sellers here on the forums. They are charging more because they have a reputation of having great worksmanship, excellent service, and good morals. Certainly, if you were to have bought the components by yourself and done all of the machining, etc. on your own, you probably would only have put ~$90-100 into it. I've done the same thing before. I ended up selling the laser (similar to yours) for about $130 (I hadn't removed the anodizing, but it had a copper heatsink, came with batteries, etc.).
I'm not saying you overpaid. You got a decent deal from them (they are always decent deals from those two). But because you are trying to resell something that has been modified and you're not a well-known seller here, you're not going to get premium.