Currently many of us are needing to build our decks and increase our collection power(CP) to reduce rents and move up leagues.

Collection power in a Chaos Legends pack ~119 - 190 CP

119 /$4 = 29.75 CP/$
190 /$4 = 47.50 CP/$
Here are a couple of links I found on collection power per pack.
https://peakd.com/hive-13323/@cylcops-guardian/how-much-cp-will-i-get-from-a-chaos-legion-pack
https://peakd.com/splinterlands/@yoog/how-much-collection-power-does-a-splinterlands-chaos-legion-pack-give-on-average

Peakmonsters shows CP/cost ratio

Peakmonsters has a selection under the Buy tab to sort by CP/cost Ratio.
Currently there are many of the new cards between the 50 and 70 CP/$ range.

Build your deck purchasing great cards.

One method I have used to build my new deck is to look through all the new cards and select 3 or 4 from each splinter that I believe I would use in most battles.

This list then makes up my to-buy list. I then place these in a spreadsheet and sort buy CP/$ to find what I perceive is the biggest bang for my buck.

Prices have fallen the past couple of day but seem to be stabilizing.

I feel happy if I am buying great cards at above 30 CP/$.
I feel great if I get one of them at above 60 CP/$.

Summoners will cost more

My target is level 2 summoners.
5.7 * 5 = $28.50 Kelya Frendul
7.6 * 5 = $38.00 Obsidian
Each gold card starts as a level 2. This makes the gold cards probably a better deal.