Building on the cheap (not a house)

Has anyone done it?
We want to errect a shower block and right now the cost of the septic tank as put the actual builing itself on one hell of a tight budget (instead of being 1/4 or the initial budget, it is now looking to be 3/4 of it)
We need a builing to house 6 toilets, 6 showers and a cooking area. I am quite happy to errect a kitset builing myself. In addition it will obvioulsy need either a concreate base or putting on pile (the latter may br the easier option if we go for composting toilets)
Help please on cheap options, I will happily do the plumbing and the electric work myself (yes I know I will need to get it signed off)

Some ideas:

Do you have any local trainee/educational organisations nearby that specialise in the building/plumbing industry? Sometimes they look for off site work to test their trainees with, rather than keep setting up and pulling down projects at the education facility...

Generally it is expected you pay for materials.

have you considered purchasing (possibly at auction via Grays online or even telephoning around to see if the businesses are selling older stock) a mobile showering unit, sometimes they get sold because of being excess to requirements or have come off long term projects.

Last week we went to a field day out west here in NSW. The toilets, instead of portaloo type facilities, were on the back of a semi....

Very portable!

I don't think there are any training organisations near, there probably would be one in chch I guess, might be worth a try.
I did get one estimate for a new mobile shower block and it was going to work out more expensive than a building, but it I could find one second hand that would definitely reduce the cost.
Thanks for the suggestion of grays online, I hadn't heard of it before

I know that Chch polytech does or used to build houses. You could try them.
Troll "that" site and you may gradually pick a lot of material and whiteware cheap. Try the demolition and 2nd hand places.

If trolling through auction sites, be aware of what you would normally expect to pay, not just their "recommended retail price", I (usually) bid for wine etc and found their rrp far dearer than what you can pick up from businesses that have good bulk buying rates.

I was watching a computer auction recently, started off well, however some of the bidding actually got as high as the normal retail rate.... same with 1000 thread count sheets etc. I do watch for a bargain..

Know your stuff, and you can do ok though, but allow for buyers premium and delivery costs etc. Not that everyone would want a portable shower block, but hey, ya never know!

Good luck and have fun if you do!