look into charter flights to margarita or caracas from places like germany, netherlands or UK is your best bet. CONDOR flies for about 1500US return i hear.
Also check venezuelan airline CONVIASA .. i think they from madrid.
the change control thing doesnt work as well as in years past due to ven. government charging huge airport taxes to airlines. That said i am sure there are some deals around.
As far as i know you can no longer buy flights from venezuela agency with bolivares to venezuela originating from out of venezuela.
... 2 years ago my wife and i flew to NZ from Caracas for about 1300US$(return for both of us!) , now that same flight is around 7000US$ .... (tickets brought with Bs from venezuela and leaving)
I know several travel agents who are very reliable , if you PM me i can put you in touch if you want to see what they can do.
Take large cash bills (50's and 100's) to venezuela and change there (with someone you know well and trust). forget the bank card or it will be VERY expensive.