Want to sell some sites, but I use a paid backlink program that people would have to join!

I was thinking about selling some of my sites but I use this service called ezarticlelink (backlink service) that people who buy my sites would have to join to keep the backlinks.

This service also has the option of putting an article directory on my sites so some of the sites I want to sell have article directories on them and some of my sites just have backlinks from this service but no article directory.

I am wondering what people would think about buying a site with an article directory that is unrelated to the topic of the site. The domains are ranking good with the article directory for the domain name. But people would have to pay about 30.00 month to stay in this program if they buy my site. They do have a free program also, but they will probably loose some backlinks over time as some of the sites fall off the program, but they can keep the directory on.

I am just confused as to what to do about these sites that have these article directories if it lowers the value of the sites??

Also because I have a lot of backlinks to these domains (without directories) but it is through a paid service...does that lower the value.

I have never sold any sites before, but it is an area I would like to get into.

Also what if the buyer of my site wants to join the paid part of the backlink program, is it unethical for me to ask them to join under my affiliate link???

I am just nervous about selling sites that I have used this program on...not sure why???