Hi Lynnek - I have sent you a private message - jules47

Gday Lynnek

2 suggestions :
South of Perth is a dept campsite - Baden Powell just out of Dwellingup- some call it Lane Poole. We spent last week there in their new camp site which you have to book online - $13.20 per night for 2 pensioners.
North of Perth is Club Capricorn - just out of Yanchep - Caravan site is $25 per night. Right on the coast and always a few beach fishermen there trying their luck.

Then there are a few other sites like Ellendale Pool - east of Geraldton, Kwolin - out past Quairadin - I camped near there at Kokerbin Rock, but they have since shut it down and re-established Kwolin.

Trust these give you some options.
Glen

Fantastic! Thanks for your recommendations Glen. I appreciate your help.

If you can travel an hour or more each day into Perth, there are a heap of sites - both National Parks and caravan parks that are $25 and less a night - especially if you work up an arrangement with a private Park. You can access all the Caravan Parks in WA (and Perth) through the Govt funded tourism board - just go on-line. You will often find their day rate is perhaps $30, dropping to $25 for a week and then a lot more if you commit to 3 mnths - just stay away from the holiday areas (the beaches usually) as we're running up to the school holidays and rates will go into the high season.
The other option is house sitting where you can park your motorhome or farm stay (these are generally free and power, water, phone supplied if you feed their pets and maybe weed their flower gardens and feed the fish. There are specific on-line sites offering these facilities, including Grey Nomads Employment which often lists some.

Good luck with the search, but you shouldn't need to pay mega-bucks to the inner city parks

caravan park at Goomalling was $50 per week for pensioners when we were there 2 years ago.

we did 2 house sits which took up all of January last year in the southern suburbs - looking after dogs - a great way to save - stretch out and keep cool. (Company called WestCoast Pet sitters)

Goomalling CP now $140 a week less $20 if pensioner or CMCA, we were there a couple of weeks ago and it was "dead", old caretakers have left too and gone to Narrogin.

Advent park is not pet friendly, but probably a good option if no pets.

Thank you all so much for your suggestions and recommendations. I really appreciate your help.

Ravenswood b/w Mandurah and Pinjarra has a shady c/park right on the Murray River - no dogs and bookings made at the Ravenswood Hotel which is about 500mts away. Think it was about $190 per week.