Hi, can you give us the update if it's possible to apply by our own. As I am considering of doing the same.
Yes, encourage you to apply on your own - it was very easy to apply. Absolutely no need for an agent as no sponsor required. As sifus on this site like Marcus have mentioned, applying on own is significantly safer for your personal data, and you have full control of any further actions you may want to do in the future.
Stay permit (ITAS) is emailed almost immediately after you enter Indonesia.
Next step is to get SKTT issued (at Dukcapil - for Jakarta the office is on Jalan Letjend S. Parman). This has to be done within 14 days, and if you go in at 8 am you should be out by 8.30 am.
You'll have 3 months to go to the Kantor Imigrasi with proof of funds. i.e., deposit in national banks - there are about 4 or 5 of these. BRI seems good. You will need a letter from the bank confirming the deposits you hold.
I would suggest to complete the 'Proof of funds' part within 2.5 months. You will need to hand in your passport for a stamp - this takes 5 working days. Plan for three visits - First time I went they advised on the formats/documents required, second to submit and third to collect (anyone can collect with receipt). Photo/fingerprinting is not required.
At every stage - whether at Immigration or at Dukcapil, I found the staff to be professional, polite and very helpful.