Write new plugin for nodebb

I have some plugin idea. 1. Ads after 10 post comment. - Load banner ads after 10 comment. Like this. [login to view URL] 2. Gpoint. - Gpoint is gift point. - The Gpoint can get by day, like post number of member account (allow topic/comment). - System auto give gift point to member account. One time per day, after member login or active. If member not login, member can't get Gpoint. - Gpoint can buy item in Gshop. - Gpoint can't transfer to another account. Ex: Peter post 4 topic and 50 comment in all time. After login or active in forum. Him can get 54 Gpoint per day. If Peter post more content, him can get more Gpoint in next day. 3. Gshop. - Gshop is gift shop. - Admin can set maximum Gpoint can use per day. Ex: In one day, one account only can use maximum 10.000 Gpoint. - Gshop sell the gift card (code and serial number). Ex: Amazon gift card, Itune gift card. Ex: Shop > Itune gift card > Card 10$ (1000 Gpoint) > Card 20$ (1950 Gpoint) > Amazone gift card > Card 10$ (1000 Gpoint) > Card 20$ (1950 Gpoint) ======== Please tell me price for write this plugin and how long for do that.