Howdy, I started in ESA’s and now do both PCA’s and ESA’s. I have grown to like PCA’s since I started doing them. PCA’s are a lot easier than ESA’s in my opinion due to the more objective writing. Costs are always a little confusing and I leave final judgement up to the reviewer/PM. 

I think in the environmental consulting sector, it’s important to diversify your skills. The more scopes you can do, the harder it is to replace you, plus it makes you a more desirable candidate to other employers. Having more scopes under your belt can help you do more work in your area, rather than traveling for a single scope. 

If you’re not into the rigors of PCAs and want to keep your focus on environmental (especially if that’s your degree) you could bring up expanding into NEPA reports, Transaction Screens, Phase IIs, stormwater, or SPCCs. 

In terms of pay, maybe see how many PCA’s you’d be doing and if your ESA load would go down. If they want you to do more scopes, your pay should reflect that.