I'm looking for a cheap suit, if it gets me through a year I'll be happy. Basically I'm halfway through a diet so I'm planning on being a bit smaller 6 months from now (all sarcasm unappreciated Looking at 0.5mm steamers similar to these, anyone tried these? How are they in the warmth department? Would they get you through the cooler months in Thailand or are they just a waste of time?

0.5mm - brrrr, I dive in my 5/7 semi dry as my shorty was just too cold.

You will be fine. I had a similiar one from Scubapro for 2 years, second year it was a little refreshing in some Pool Sessions in winter time , but still no problem in the ocean.

Steamers are great since they give you full body protection against stingers. I've got one of them myself but in the colder, monsoon months I use a 3-4-5mm suit. The rest of the year just shorts and a rash vest for most dives and sometimes the steamer. Scubapro has a nice one.