is that the only way to do it in unity?
what?
do you have to pay to put microtransactions in your game?
No it doesn’t. Depending on what platform you’re developing for, you’ll have to integrate the proper SDKs. If you don’t know how to do that, then yeah you’ll most likely have to get help from a third party or use a plugin from the asset store/prime31.
how would I integrate the proper sdks and would it cost from the asset store?
It WILL cost if you don’t know how to implement them and don’t feel like learning your way through it. Which SDKs you need to integrate are relative to what platforms you’re developing for. Unfortunately, I left my wizard wand at work tonight and I won’t be able to guess what platforms you’re developing for.
I’d be using XCode for iOS and Android SDK for Android. I’d like to learn how to do it
There are no easy answers for the implementation as far as I’m concerned. For iOS you’ll need to integrate the StoreKit framework, as for android I am not sure.
OpenIAB is a good free solution for in app purchases.