Now I haven't been to PoCo Surplus or Warcraft Games but everyone seems to think they're both great. If you want to buy local then it's right there.
TBH There isn't much you can do other than saving your money.
I highly suggest you stick to the original plan and get a regular G&G or wait a few months til you're 18. You can still rent rifles you know. "3quip" does rentals so you can probably pick one up for the day and see what happens, maybe you like it maybe you don't but at least you only rented and if you don't like it then it's not like you dumped $500 into a gun that sees one use and no one wants to buy since it's "inferior" and if you're AV'ed you can get full black metal guns (and in the future black guns from certain sources because of some new developments in RCMP/CBSA policy).
Only other thing would be to buy a "3D instruction manual" (AKA the Kraken) and upgrading parts slowly over time. You'll end up spending more money on it though than if you got a "high quality" gun like that G&G right off the bat.
ಠ_ಠLess QQ more Pew Pew
READY TO >> RACE