Two fold I guess, going all steel upgrade parts will cost you a bit.
Could always toss the WE and upgrade to a GHK
/ghkbias
alternative, see your costs, since CAD is low, you may not find everything you need here in Canada, so... if it's going to run you 400+, I would just upgrade my platform.. personal preference.
Else you can go the cheaper route and use the open bolt kit and replace everything.