No dive operator will admit to offer "discount" openly.
Diving rate is certainly NOT cheap in Phuket. But there must be various reason for that eg. distance of the sites, food, picking up divers from various places etc etc.
However, the big discount in hotel room during off season really offset the diving cost.
Wouldn't it be more prudent if the question was raised between concerned parties ie Op and the dive operator?
I am not picking a fight but I do believe the original question was un-necessary.
I realize that dive operators are not going to offer discounts if they don't feel they need to.
That is why I thought I would ask here for peoples experiences first. A common opening reply is that there are no discounts, even though they may be regularly given. That is what negotiation is about. If I know they don't, I won't bother. If I know they do and have a sense for the level they will normally go to, I will negotiate accordingly.
If they are in the practice of allowing discounts, it will be built into their rates regardless of whatever other costs are in their cost base, and will already be a factor in their profitability calculations. If one site is more costly for them to service than another, they will also factor this in.
I am inclined to pay a fair price for service. I am not inclined to pay more than necessary. Asking about other peoples experience is a perfectly rational approach to determining what I should expect to pay.
The price of hotels is also irrelevant and a separate issue. Having been to Thailand before I am fully aware of the fact that I can spend as much or as little as I want for a hotel, and I know what to expect at each price point. What I pay a dive operator has nothing to do with what I pay a hotelier.
Lectures about how I am uncool for asking them to take a hit, or how I am going to be responsible for the degradation of the Thai diving industry, or how it is unnecessary to dare to ask such questions are unhelpful.
I am disinclined to carry this conversation further.