Im going to Thialand and thinking of byeing a dvd player while im ther are they cheaper and whats the pros and cons

They maybe a little cheaper, but I doubt that much.
With the cheap ones you can get over here now days its probably not worth the hassle.
And the expense of changing the plug, not sure how much prob a couple of £

Also there is probably little to no warranty once you leave Thailand with it, As a lot of companies will only give warranty in Asia but not Europe.