if its only bubbling, then i'd rub it down yourself, treat it with krust or something, and then primer it, rub it down, and get your paint patched and a rattle can made up, and flash it over yourself... i wouldnt pay paint shop prices for stuff like that... but if its gonna need welding, then why not just buy a new front wing, get the paint shop to match up your colour, spray it for you, then fit it yourself, litrally take all of 10 mins to fit one...
wouldnt worry about the bumpers, they are plastic so wont rot, just concentrate on the simple stuff first...