"Money doesn’t motivates us to help each other with R" This might be the case. However, If you aren't paying someone for development, they will most likely on

"Money doesn’t motivates us to help each other with R" This might be the case. However, If you aren't paying someone for development, they will most likely only be able to work on your project after the bills are paid (and if they are married/have kids, this means they will have even less time to work on it).