Not that bad if you do most of the mech work yourself. Biggest purchase is just buying an svx to pull the guts from. I’ve bought many from 6-800, running, but blown gearboxes. If you MS it, then you just need a complete motor. you can partout an SVX and make back 4-600 prety easy on SVX forums.
Other than that and an aluminum rad, exhaust work, misc hoses, etc, it’s mostly drop in. It’s expensive when you do what I did. Your car you need to ditch the AC and put the alt where the compressor sits to clear the hood( see Laverty’s car on EFI logics site) WRX had more hood clearance and wasn’t necessary.
You could probably sell the EJ25 and cover 80% of the costs IF you do all the heavy labor yourself(gutting SVX, installing motor, etc, etc) Hardest part is just weeding down the SVX harness, but I’ve got that to a science after doing a dozen or so.
I’m going to do another in the future, but with a 3.0R motor destroked. My old one was by far the most fun car I’ve ever built for myself. Still cutting my ballsack for selling it, especially since i see it nearly every week 