.30 cal P-rod

Unless you really want to do it just to do it its not going to be worth it in the long run. Sure, it might shoot well but for what it will cost you you could just pick something up. I put a boatload into my M-rod and sure its a real nice shooter but its still an M-rod. It is not even close to my vulcan or Edguns or even my compatto for example. I did it and it was fun learning the ins and outs of a PcP airgun but I would not do it again.
 
A Marauder 25 cal was my first pcp, second gen. I threw all aftermarket performance mods at it within the first month of ownership. I would do it again, for sure, as that gun is not only so very easy to work on, it reacts to mods well, too, provided you go at the modifications with a well thought out plan and just don’t throw parts at it. Hey, if it is still a Marauder after a grand worth of parts are thrown at it, and can be made able to shoot like the more expensive other guns out there, to me that’s a hoot! I’m just glad that there an awesome aftermarket support for these, along with great customer support. 

Go marauder!
 
Years back before the nice 1k air rifle came out It was worth building the Marauder. I’ve been there and spent a lot of money on each of my Prod and Mrod. 

Now for around 1k you can get a much lighter, quieter, with more shot count and accurate piston or rifle. 

It was a great leaning experience and I would do it again under the same circumstance.