Hi, @Naveendagar Yes, I am active on the forums, because @pradeepkumar bro has created an awesome forum
There are several factors that you need to keep in mind..
1) What's your Budget?
PBNs and Web 2.0 can get very expensive. Does your budget permit you to use them? If Yes, then you need to look into your ROI. Would build your own PBNs and Web 2.0 worth the investment to rank Event sites?
2) The ROI
As I mentioned above, calculate your ROI. You need to have some basis. PBNs will definitely help you give a tremendous boost in ranking, but can get inexpensive.
3) Looking Term vs Short Term Event Sites
What kind of keywords are you target? Happy New Year or Happy Year Year 2017 (Year).
If you pick option one, then that is long term and investing into PBNs would be completely worth it for you to build your own PBNs.
..but what if they are for short term?
Instead of building PBNs, opt to purchase links from Quality PBN seller. It will cost you anywhere between $5-20 per link, but would be totally worth it.
Also, you can purchase expired web 2.0 and purchase contents and build on them. This won't be much expensive.
Here is a pro tip: Don't build all your Web 2.0 on expired sub-domains. Mix them with new ones to look legit.
If you still have any questions then let me know, would be happy to help