Annex - Cost to Manufacture?

[Beatle]

I'm looking to buy an eighties-era Jayco Swan (when I can find a decent example).  Most have annexes only the length of the van body.  I'd like to get a full length annex made up, so it extends at least from bed end to bed end.  Also, if I raise the suspension, any original annex won't reach the ground so I'll be up for cost to modify the annex anyway.

Now, most of the original annexes are full canvass, but a lot of modern caravans have annexes made from vinyl looking material (to match the pullout awnings).

So, a couple of questions:
Is the vinyl a good option compared to canvas?
Is the vinyl cheaper than canvas?
Seems vinyl would be lighter?
Is it long-lived?
Downside would be that vinyl sweats?
What would be a ballpark cost to get an annex made (I'm thinking 20' long with a couple of separate zipped panels for versatility, end and side screened windows)?

[GUEY]

If you ring these guys they do something like what you are after. And will be able to give you a price.
www.allseasonsvinyl.com.au

Pics here. https://www.kakaduannexes.com.au/rvs-caravans-and-campers/camper-annexe/

Bar from that I can't help to much. We have vinyl walls and find them ok. Don't get used very often.
The biggest upside I see to vinyl is that it is very easy to clean and also to dry off if you have packed up wet. Just grab a towel and wipe them down or dry them off.

[BrindiCruiser]

I spoke to am person who had his made up in a mix of canvas and shade cloth. Full length from end of bed to the other bed. $2500 from a small business. Sorry can't remember the details.

You could also try budget bed flys but they will need to have your camper on premises.

Kakadu are quite expensive, but have a good rep. Their site also has some info on vinyl vs canvas.

[wholehog]

there is a guy down here on the Central Coast who i spotted the other week,i had to drop in to get something done and got to chatting,turn out he was making caravan awnings for some mob...In Vinyl...
Anyway its not to far from Medowie(Hope u fared well in the bush fires last week)
Long Jetty Canvas was the business....sure u can find it in the yellow pages

[Beatle]

Thanks all, looks like a budget of $2.5K is required.  Gives me an idea for haggling prices.

Wholehog, thanks for the concern with the fires.  I didn't suffer any damage, but I could certainly see and hear the flames from my driveway.  Another street over and it may have been a different story.