Your grammar is fine Nicoolivia,
Well done you.
In my experience, Indonesian stamps do not command a very good price in general, which has its advantages, one can build a very good collection at low cost, but not good for selling.
The caution with that statement, is the odd Souvenir Sheet/s that command extraordinary prices.
Damaged stamps in a collection can be a detriment to the overall value of a collection, glue and tape are a real "no,no"