What are the fees for a transaction?

Using LOBSTR does not add any additional fees for the end user. Deposits and withdrawals are free.

The regular Stellar transaction fees still apply, however.

To prevent spam, each transaction on the Stellar network costs 0.00001 lumens. This can result in what looks like an uneven balance in your account.

Read more on Stellar fees here: 

https://www.stellar.org/faq/#_What_are_the_fees_for_a_transaction_

https://www.stellar.org/developers/guides/concepts/fees.html