TRV refusal and want help to resubmit in next 3 month

[koolkid]

1st application:
Applied online from Jamaica on August 14th
Bio metrics on August 19th
Refusal and correspondence letter on August 29th
The reason for refusal was 'Purpose of visit and personal assets and financial status.

The Purpose for my visit used was to visit my brother who is a PR and his girlfriend that a citizen of Canada.
It was to see him in time for his birthday and also to see the country of Canada such as visiting some of the places there.
My financial detail used was $2300 Canadian dollars in savings for an 8 day trip. Employed for 1 year 10 months with earning close to $900 Canadian dollars per month.

I have another brother in Canada that would be having his graduation in December and thinking of using this for reason of visit. And would like to know whats the best way to go about this and any advise is appreciated.