How much do you intend to shoot and what caliber?
For us old folks that are members of the "Ibuprofen" chapter of lifes bike club pumping is getting old fast!
We tend to work some hours extra and go for a mechanical device that ends up in stored air. Some which has a good diving or paintball shop nearby ends up with sweet deals on 4500psi fills, the rest of us must learn to care for ourselves ie. a compressor of some sort.
When i started to reload firearms ammo for myself i thought i would end up saving a ton of money. No Forrest!!! I spent the same and ended up shooting a lot more. Same with PCP, with a booster and a good size 4500psi bottle i just shoot way more
It's kind of like skipping when buying glass.
Buy the cheap scope and replace it at some point just to upgrade again and again until you have spent 2½ times what the right scope will cost from git go.
Drop the pump and go for a 4500psi tank and cough up what is needed. Find a place that will fill and be content until you deside to get selfsufficient with a good compressor or booster.
You'll be much happer and end up spending a lot more time shooting and that is what the whole thing here is all about ;-)