Hi @kripto-mir,
Buying upvotes can be very risky as you do not get the upvote or attention you intended. I have never used the service but my friends who do, none of them got an extra upvote by getting their post promoted. Instead they attracted the attention of flagging buddies.
There should be other ways of raising the rating of one's post other than promotion.
You are mistaken, for example, you had little chance to notice this post if I did not make a promotion.
How much did you risk to get this post on the top. I don't think I'm willing to because majority of it will be going back to the bot or betterstill, loose than I would If I didn't promote.