Unfortunately, there is no guarantee when it comes to solo ads. It highly depends on the sellers you choose, the targeting data that they posses (Who knows who are they advertising to? are they even interested in what you are promoting? or just clicking to quickly check it out?).
There is never a perfect way to know if traffic on udimi is warm or cold, and whether it is going to generate sales or not. Especially when promoting high ticket systems.
Products that cost less, have generally a higher conversion rate, therefore you might also want to try different clickbank products, and test your udimi providers