This question has a lot of answers, but the best option I think is along with doing your "TO-DO LIST" which gives you 450 something VPs including daily, monthly and weekly actions; you can go for 4-5 packs of 10 T Credits which gives you (239X4=956/ 239X5=1195) VPs with the minimum cost of $5.6/each i.e (5.6X4=22.4$/ 5.6X5=28$).
