the cheapest way would be for you to do it yourself..
replace the two doors.. it may be possible to salvage the front door but it would take alot of time to fix..
take off the rear wheel and hammer out the wheel arch with a piece of hardwood and a hammer..
the hardwood wont stretch the metal anymore and you can also shape the wood to create the shape your trying to make in the wheel arch..
the metal will already be stretched in that area so youll want to hammer it out so that its not quite all the way..
then fill the rest of the way with some bog, sand it smooth and paint it..
the dent in the side skirt wont be possible to get out without cutting it out and welding in a new piece so id just leave it..
the dent near the fuel filler looks like it could just be pushed out, hard to tell from a photo..
it all depends on how fussy you are and how cheap you are
most insurance repair places will do it like this, its just they have better tools and more practice..
look on youtube for some demonstrations i know there is a new zealand guy that does them and is really helpful..