Has anybody ever put his app on AppSumo? What are your thoughts on those deals from a makers point of view?

I have user constantly asking me to put my app(s) on AppSumo. I don't like it as it feels like a sellout and is not sustainable but am I missing anything here? Could there actually be an advantage (for indie makers)? Marketing wise or other?

Depends on your running costs to sustain those lifetime deals. Some also offer the option of stacking deals. Like buying multiple times and then redeeming it. That's probably for covering more costs.

Provided, you are ready to scale. It could be a very nice way of getting your hands on some extra cash which you can invest in your business to accelerate growth. I definitely would offer a lifetime package of some sort for my products when they are ready.

OK, so how would you price a lifetime deal? Would you go for a very simple/limited version of your product?

Like if my products is about websites and different plans about number of websites. I can do something like $X deal for 2 websites (stackable upto 5)

but with the full feature set?

Yeah, otherwise people would simply request it in the comments & won't buy. Haha..