SliceWP

SliceWP is a WordPress affiliate plugin with a pricing model that stands out in a category full of feature gates: every plan includes all features and all add ons, and the add ons cannot be bought separately. You are choosing how many sites you need, not which capabilities you are allowed.

Pro is $169 a year for one site with email support, discounted from $229, or $429 once for a lifetime licence against a $589 list price. Pro Plus is $259 a year for ten sites with priority support, or $649 lifetime. Sale prices apply to the first year, with renewals at full rate, which is exactly the situation where a lifetime licence starts to look sensible: at $429 once against $229 a year, it pays for itself in under two years.

There is a 30 day money back guarantee and free plugin updates while your licence is active, with a discount if you upgrade tiers later.

Like other self hosted options, the data stays on your site and there is no percentage taken on referred revenue. It is a smaller project than AffiliateWP with a correspondingly smaller integration list and community, so check that it connects to your specific membership or ecommerce plugin before buying. The lifetime option is the reason most people choose it.