Find a AMO with a German speaking/reading LAME first, give them the short list of things you are interested in.
Get a detailed estimate including you and LAME looking at several aircraft over there, return to Australia and get final estimate.
Seem a expensive way to go about it, but only way it might stay within 130% of estimate and maybe even close to estimate. If not work on 200-250% of purchase price of a near 20 year old Cessna piston single (due sids due at 20 years = do it while in bits).