If you want to level up an Epic above L20 it will cost you considerably more DNA per level than a leg-end or unique. This to me seems utterly insane and limiting, making all Epics have a builtin obselecense and shelf-life at around L22/23, especially considering how many times you just get 10 DNA a pop.
For example to upgrade Stegoceratops to L23 costs 1500 DNA, and to level up Tragodistis to L23 only costs 400 DNA
Unless you want to grind a lot, it’ll take a very long time to utilise Epics at a mid-high level. Which is crazy because it severely limits choice.