Seriously I've been down this road, it's not worth buying them most do not work or you get poor results, just make your own fresh one using the timespan feature in scrapebox, scrape a load and comments, put them in the keyword module, set time span 1 month, harvest, post, get the posted, then use the site: operator, repost, after this then use your real link and blast away. People don't spin comments, using comments as keywords will get you auto approve platforms easy. And using the timespan, increases the chance because its fresh stuff not years old, you can even go one step further, instead of blasting your real link at this stage do a backlink check of all the posts on the page, chances are if they know this method, they know what they are doing, so likely they got a few good links pointing to them, then just go and take them.
If you do want to buy them ask how many times they have been sold, then search to see if it has been shared for free, if this is the case, it will be spammed and pointless, if you want to pay money for this type of thing, get someone to personalise it just for you, and make sure it's only sold to you and no one else. But like I say best to do it yourself