Friend of mine was into gas helis for a while.
Apart from the support equipment, they were about $100 a crash after that...
$100 is a good bet for something 450 sized. A small 'tip over' you may get away with main rotor blades and a feathering spindle. Now depending on if you are flying china junk blades or $$$ carbon, ymmv.
An actual crash expect stuff like rotor blades (main and tail), feathering shafts, fly-bar components, main drive gears, main shaft, skids, tail boom, canopy, canopy mounts, swashplate, linkages for starters... Servo gears too depending on if you are using metal gears and how hard you are whacking it.
This gets expensive quick. I actually learned to fly before sims were widely available so I've paid my dues 10X fold.... :D
I've not had a CP heli before, I did have a toy grade indoor one that had a swash plate but was still variable RPM and not 3D capable. I've got Aerofly 7 running on my laptop and managed to get it working with the TX today. I had a crack with the trex 450 in the sim and it's certainly not easy. Tbh flying wise I'm more interested in scale and maybe speed running. I'd love to do a scale UH1 conversion on the 450 especially as it's an older flybar version. I used to be a mechanic on Hueys and have quite the soft spot for them.
I started the tear down earlier, I'm reasonably sure it's a 450 SE V2 but all the electronics are rather dated, with a 35mhz TX/RX and all analogue servos. It's come with a hell of a spares pack, there's enough stuff to build a complete second heli, half a dozen sets of blades, a few tail booms, servos, gyros and tons of other bits and bobs.
Definetly put in some serious sim time. 450's are not very scale like at all as they are very quick and agile. You want to start with small-er control throws and lots of exponential. Learn where your hold switch is and practice that as a go to if you feel like you are going to auger it- much less damage will ensue if the drivetrain is not under power when things meet terra firma. Start and practice in normal flight mode (little or no negative pitch available)/tune your head speed so it isn't screaming - this will lessen some of the intimidation factor. Should be plenty of parts still available for the 450 v2 and clones. At one point I had enough parts to make 4-5 of them, lol. 450 clone bare airframes use to go for $40- great for spares (hobbyking). You mentioned 35mhz, what transmitter is it and is it a computer radio? heli-specific?
The bigger 500+ sized birds are actually easier to fly and much more stable- much better presence in the air too as far as orientation. Something to work up to once you gain some experience, and much better for scale imho. The danger factor goes up a bit too in this size range as there is a lot of power and rotating mass.
But yeah- it's an awesome hobby and once you get the hang of it pretty rewarding. Just don't be discouraged initially. Lot's of guys fly planes (easy), even more the drone thing (mindlessly easy). But it is a bit a badge of honor to be able to skillfully handle a CP heli.
Got me wondering if Waterhead can pilot like that in real life-
Full scale heli's cannot achieve the fully symmetric pitch curve (full negative pitch) like an RC can. So no inverted hovering or negative punch outs.